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Old 09-24-2002, 11:43 AM
PhilSine PhilSine is offline
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This topic was prompted by a post a few days ago concerning an alternator upgrade.

http://www.ifsja.org/ubb/ultimatebb....2;t=013185;p=2

I did my best to state the facts about the FSJ's with the ammeter as they exist but was falsely contradicted.

It appears to me that many in this forum and abroad do not fully understand electricity and its principals of application. Many do understand the basics of AC or DC and where it is used etc. but have not had it fully explained to them as it applies to our FSJ's or automotives in general.

So, to help any out who may be curious, here it is.

I will begin with the source(s) of electricity.

1) The alternator- There is not a single component in your FSJ that cares what the potential of your alternator is so long as it has enough reserve current to supply that component with the current it needs to operate. That means that when your blower motor, AC, headlights, hazard flashers, tail lights, horn, cigarette lighter, tailgate motor, power window motors, and anything else I left out are all operated at once with the engine running and they want a combined 80, yes, 80 amps, they all don't care what happens so long as they get it. Your alt may care a bit but not too much as it really has little to do with all that. The job of the alternator is to maintain the charge on the battery when all these components put a draw on it. To repeat....

The job of the alternator is to maintain the charge on the battery when all these components put a draw on it.

Your alternator does not directly power your vehicle under normal conditions. However, if you disconnect your battery while the Jeep is running your FSJ will stay running as the current that was going to recharge the battery is now dedicated to running the systems.

This is fact....Look it up if you do not believe it.

2) The Battery-The battery is the primary source of power to your system. It is drawn upon by everything whether the vehicle is running or not. It gets recharged by the alternator(I know, already stated). The battery is a huge reserve cell of electrical current that is readily available for use by the components needing power. That is why a battery is capable of producing a lot of amps all at once. Anybody here have a battery of less than 700CCA? There may be a few but that's probably because either they, or the DSPO didn't know better. The reason our batteries are so large is that a large reserve is required to operate all of our systems optimally. Heck, just starting our rigs requires about 200A (that is the largest single draw our rigs need at any given time).

Recap-Under normal operating conditions the battery is the main power source for an automobile and is recharged by the alternator.

HOW DOES THIS TIE INTO THE SYSTEM?

Here's how it goes.....

When the FSJ is not running all power comes from the battery and it has no source of recharge until the FSJ is running. When the FSJ is started the alternator immediately recharges the battery and maintains that charge as long as the engine is turning the alt's pulley. When the battery needs a big charge the ammeter will reflect this by jumping way to the right for as long as it takes to recharge the battery and slowly come back to center as the charge levels out. When you turn on an accessory you will notice the ammeter jump briefly to the right again and slowly return to center as it makes up for the initial draw on the battery. Remember the example I stated above with all the accessories on? Together they will draw around 80 amps. How can a 60-amp alternator make up for this? It can't. But, it will make up for 60 amps of it and your ammeter needle will move to the left to 20 amps which reflects the additional draw of 20 amps on the battery that is not being made up for.

What if my alternator is bigger than 60 amps?

Well, say you have a 135A alternator like, well, me. Then with all accessories on and the engine running the ammeter needle will jump up to 60 for about 1 second and within 5 seconds be close to center and after about 30 seconds be close to dead center. But why? Remember, the battery takes a big hit at first and the alternator takes a couple of seconds to fully recover from such a big hit. If you only turn on one accessory then the hit will be small and the recovery will be even faster.

Why does it take such a big hit at first and not maintain that draw?

Because an electrical component requires the most current right at start-up but requires much less to stay running. A 10-amp continuous draw motor may draw as much as 30 amps in the first millisecond it's turned on for. But it will immediately drop to the 10 amp operating current right after that.

So can I run my vehicle with all the accessories on for a long time and not damage anything?

No, after a while the 10GA wire that feeds the main fuse box will overheat and eventually melt down. Your alternator would keep the battery recharging and your battery would not have time to drain down to the point of any damage or even to the point where much wear is imposed on it.

A 10GA wire can carry up to 35 amps continuously within a run of 4-7 feet. In a run of less than 4 feet that capability increases to 50 amps. Automobiles use wire that has a more industrial insulation that is more resistant to the effects of heat so in a car, those ratings may increase by about 15% but that's still not enough to run everything for a long time.

What if I add a separate fuse box with a bigger gauge wire that gets its power right off the positive terminal of the battery?

Then the limitation of your alternator coupled with the normal current draw of the rest of the system is your only limiting factor. With all needed accessories running in the worst condition (Night with rain and cold out) your current draw through your normal part of the system will be about 35A. Anything else you may want to add to the system via that independent fuse box depends only on your alternators ability to recharge the battery.

What about my winch that draws 200A?

Well, a winch is only used for a few seconds at a time (hopefully) and as long as the winch is not run through the normal wiring then there should be no ill-effects on the system except for that which effects the draw on the battery. The ammeter only reacts to the current being drawn through the 10GA wire that feeds the system. That means that the 200 amps that the winch needs will completely bypass the ammeter and the 10GA wire that feeds it.

Now, when your alt does recharge the battery it still won't overload things as the battery will not draw the current through the system but rather directly from the alternator itself.

Electricity travels through the path of least resistance and always from a source of greater potential towards a source of lesser potential.

That means that the current will always go directly from the alt to the bat. It will not take a detour to go through the ammeter first as that is contradictory to physics.

So, hook up all you want (within reason) directly to the battery and don't worry about the rest. Just make sure your alt and bat are healthy enough to carry the load. Get an alt that is as big as you want just make sure you don't add too many accessories to the fuse box inside as the 10GA wire may not be up to providing an abundance of current.

What I have stated is fact. I have the credentials to back up what I say all anyone has to do is ask. Here are a the electrical formulas that will help you determine how much is too much.

I=Current(Amperes), V=Volts, P=Power(Watts), R=Resistance(Ohms)

Power...
IxV=P
I2xR=P (I2=I Squared)
V2/R=P (V2=V Squared)

Current...
square root P/R=I
P/V=I
V/R=I

Volts...
sq. rt. PxR=V
P/I=V
IxR=V

Resistance...
P/I2=R
V2/P=R
V/I=R

And no, I don't know this all off the top of my head. I carry a chart around with me in my wallet because I use it often enough to need the chart but not often enough to have memorized it.

I found one on line as well....

http://webhome.idirect.com/~jadams/e...virp_chart.htm

Check out the chart and poke around the web site to learn much more than what I have covered and more in-depth too. It seems like a pretty good site for the basics although I didn't see a section on digital or semi-conductors but most of you will never need to know that anyways.

Hope this helps to clear-up a few uncertainties about how things work.

[ September 24, 2002, 05:50 PM: Message edited by: PhilSine ]
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Old 09-24-2002, 02:30 PM
Sycho15 Sycho15 is offline
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Sweet! I'm adding "auxilary fuse box under the hood with a huge cable lead ran right to battery" to my list of projects for both of the Jeeps I plan to keep.
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Old 09-24-2002, 03:04 PM
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AC or DC ?????? PhilSine its AC/DC and they rock
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Old 09-24-2002, 03:09 PM
PhilSine PhilSine is offline
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Here's another web page I found that re-enforces what I said about cable size. It give an amperage rating with respect to size and length of cable. The amount of conductors per sq. inch also has an effect on conductivity but mostly in the speed department.

http://www.epanorama.net/documents/w...esistance.html
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Old 09-24-2002, 03:16 PM
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Quote:
Originally posted by PhilSine:
With all needed accessories running in the worst condition (Night with rain and cold out) your current draw through your normal part of the system will be about 35A. .
..
PhilSine:...
What you have written sounds correct to me. In Texas we run the A/C on hot rainy nights. The A/C clutch is an Electro-magnet and I would guess it (together with the blower-fan )would draw a bushel of amps.

... Also it seems a few guys think electrical radiator fans don’t require a draw on engine horsepower like the stock mechanical fans do. I would guess the electrical radiator fans would use more power in the long run for the same CFM.
... Could you respond to this in ten words or less...

... CUL… ds..
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Old 09-24-2002, 03:23 PM
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Do we get a certificate or something for reading all that?
Seriously though, it's good info. Knew most of it, forgot most of it. memory's like my truck....spotty and full of rust holes.
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Old 09-24-2002, 03:27 PM
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great post thanks
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Old 09-24-2002, 03:41 PM
Bob Barry Bob Barry is offline
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One caution; the only feed to the battery on the stock systems up to '85 is through the 10ga wire that runs through the ammeter. There is about six feet of wire to the ammeter, and six feet of wire back to the (+) stud on the starter relay, which is how the battery is charged.

I have no idea how much current that much wire in typical 20-year old condition, with an ammeter in-line, is capable of drawing without melting, but in personal experience, headlights, windshield wipers and a slightly-discharged battery are enough to toast that wire REAL good.

How will a separate fusebox hooked right to the battery NOT also draw current from the alternator, either directly or by causing an additional drain on the battery that will require the alternator to put out more current to charge it back again?
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Old 09-24-2002, 04:07 PM
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Most all of what you said is correct...not gona get nick picky. I work for a company that designed and manufactures equipment for the CATV and fiber optic industry. I work with a electronics a lot to say the least (I do fix the computers..but I also work in engineering)

So I agree that the fuse box being closer will let you draw more from the batt without the side effects. Most all new cars have the fuse box very close to the battery.
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Old 09-24-2002, 04:18 PM
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Quote:
Originally posted by PhilSine:

Now, when your alt does recharge the battery it still won't overload things as the battery will not draw the current through the system but rather directly from the alternator itself.

Electricity travels through the path of least resistance and always from a source of greater potential towards a source of lesser potential.

That means that the current will always go directly from the alt to the bat. It will not take a detour to go through the ammeter first as that is contradictory to physics.

[/QB]
It's obvious from your post that you understand electrical theory. You have provided lots of good info and are to be commended for taking the time to do so. I have a degree in electronics and also work in the field but that is not really important.
On the subject of the amp meter and battery charging current: I have a 76 Cherokee and can only speak from personal knowledge for that model year. I also have a shop manual for my specific vehicle. The amp meter in a 76 Chief with a 360/401 V8 is wired in SERIES between the alternator output and the battery. ALL the alternator charge current to the battery flows through the ignition switch, the ampmeter and is routed to the battery via a large gauge yellow wire that normally connects to the starter relay post that the battery positive cable also connects to. Unless a modification has been done to bypass that circuit ALL the charge current must flow through the amp meter and the ignition switch. This stock charging circuit is NOT designed to handle the potential battery charge current a higher capacity alternator can provide over an extended period of time. If the battery is in good condition and fully charged then I will agree that there will most likey be no damage if a higher capacity alternator is installed because the higher potential instantaneous charge current will drop off quickly. However, it's not a perfect world and if the battery is in a low state of charge or defective (such as developing an internal short) then the resulting sustained higher charging current that a 80, 100, 120 amp alternator is capable of outputting will very possibly damage components in the charge current path. The damage can occur to the wiring, connectors, the ignition switch or amp meter connections. I don't mean to be contradictory but I speak from experience - been there, done that - and wished I hadn't.
If anyone wishes to install an 80 amp or higher capacity alternator in their older model Cherokee or Wagoneer, they would be wise to determine exactly how their vehicle is actually wired and seriously consider installing a direct charging path connection from the alternator to the battery or they will be risking damage to their stock charging circuit components. I would suggest installing a heavy gauge wire directly from the alternator output to the starter relay terminal where the battery positive cable is connected. Installing a voltmeter will provide the means to monitor the state of health of alternator output and the nominal battery voltage. You will have to make certain there is no drain on the battery with the ignition switch off after making this modification. I also installed an auxilary fuse block from Painless Harnesses that has both ignition switched and unswitched circuit. I don't recall right now if I had to connect the distributor/coil ignition circuit to a new ignition switched circuit but that may be necessary after installing a bypass because the battery will not be isolated by the ignition switch in the same manner as it was before the bypass was added. Another way to install a bypass is to use a hi-amp diode in the bypass circuit to only allow charging current to flow through that path but that adds another component that can fail. Your vehicle configuration may vary so take a good look before making this sort of alternator change. Sorry if I muddied this issue up.
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Old 09-24-2002, 04:30 PM
PhilSine PhilSine is offline
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Quote:
Originally posted by Bob Barry:
How will a separate fusebox hooked right to the battery NOT also draw current from the alternator, either directly or by causing an additional drain on the battery that will require the alternator to put out more current to charge it back again?
It does draw from the alt. In that portion I was pointing out that it will not affect the regular part of the system in terms of sending any more current through the 10GA wire up the fire wall and back.

Also, good point on the overall length of the run on the ammeter wire and also pointing out the fact about how age affects the wire. The copper won't break down but the insulation will.

Stuka, you're right about the newer cars putting a fusebox close to the battery. All the newer cars I've worked on have at least 2 fuse boxes. One in the engine compartment that is responsible for distributing power to the engine components, and another under the dash responsible for the interior components. The interior one is usually fed from the main one and has at least a 50A fuse associated with it.

Also, a note on running wires.
When you run wires in any application be sure to make the runs as straight and kink free as possible. Anywhere that there is a kink or a tight bend there is likely to be a hot-spot and it will be a source of future problems. Do not figure-8 coil wire and tpe it in a bundle all together. The DSPO did this to my FSJ after he eliminated the fusible link and the result was a complete melt-down of the wiring harness inside and out. I now have a rebuilt harness that has an improved, more visible fusible link design that is run in industrial grade underground interduct that will not melt when exposed to the heat of the engine.

Another tip is to use the highest quality electrical tape available. 3M Super 33 is about the best on the market and it comes in a wide assortment of colors.

Heat-shrink is the absolute best way to protect wires that have splices or ends on them but it is not always practical. They also make a heat-shrink tubing that has glue in it that will make your splice water-tight when it melts.

That's all for now.
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Old 09-24-2002, 04:40 PM
PhilSine PhilSine is offline
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Wesdog, the way you describe it is the way it exists in my 77 Chero. The output to the alt is on the same lug as the pos. bat. cable and the 10GA wire heading to the cluster is tapped from there after the fusible link. According to my diagrams, this is the correct configuration as it should also be on your 76 Chero. So, yeah, I agree with your statement and can only say that the PO must have changed it. Both Haynes and Chiltons show it the way you said it should be and as it is in my 77 (I know, redundency).

Edit....There is also a second fusible link between the lug of the starter solenoid and the fire wall.

If any other configuration exists, then the owner can expect trouble in the future. Maybe that's why Jeep went to the Volt meter in later years as it is a more accurate way of showing your overall system health without having to run the meter in series.

[ September 24, 2002, 10:41 PM: Message edited by: PhilSine ]
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Old 09-24-2002, 04:43 PM
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Phil, Phil,

Lets skip the credentials (BS physics, BSEE, MSEE, and I still can't spell for s**t) and get to
the point. You know enough to be dangerous, but not enough to stay out of trouble.

Lets break this down. Point by point:

"I did my best to state the facts about the FSJ's with the ammeter as they exist
but was falsely contradicted."

YES you were contradicted and rightly so

" It appears to me that many in this forum and abroad do not fully understand electricity
and its principals of application. Many do understand the basics of AC or DC and where it
is used etc. but have not had it fully explained to them as it applies to our FSJ's or
automotives in general."

YES Phil, and you seem to be one of them who needs alittle help in this area.

To keep this short lets look at the basic circuit layout of the charging system.
(Crappy Ascii art, for 73(?) -> 85 FSJ's (86-91 ran the alt output to starter feed
with no pesky amp meter, but still with a wire guage to small to support
large alternators in a trouble free mannor)

xxx_____xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxx____
xxx| ALT |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|BAT |
xxx|____----- 10 GA Wire-#1---|FW|-2--|Fuse|-3-|AMP|--4---|xxxx|
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|Panel|xx|Guag e|xxx____
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxx xxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx5xxxxxxxxxxxxxx xxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxx xxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|Accessory Loads| xxxxxxx
FW = Fire wall
x = white space
#1 Wire from alt
#2 Wire in back of fuse panel feeding accessory fuses
#3 Wire from fuse panel to amp guage
#4 Wire from amp guage to battery

" 1) The alternator- There is not a single component in your FSJ that cares
what the potential of your alternator is so long as it has enough reserve
current to supply that component with the current it needs to operate. That
means that when your blower motor, AC, headlights, hazard flashers, tail lights, horn, cigarette lighter, tailgate motor, power window motors, and anything else
I left out are all operated at once with the engine running and they want a combined
80, yes, 80 amps, they all don't care what happens so long as they get it."

Well most items do care what voltage they have accross them but for sake of
aggument say I follow what you are trying to say. (The potential of the alt
output does matter)

" Your alt may care a bit but not too much as it really has little to do with all that. "

Wrong "O" It cares very much how much load it placed on the system.

The job of the alternator is to maintain the charge on the battery when all these
components put a draw on it. To repeat....
The job of the alternator is to maintain the charge on the battery when all these
components put a draw on it.

Yes, Yes. The regulator sence line, looks at the potential (voltage) at #4, (Crappy assci art)
When the potential at this point is below the regulator set point (Normal ~ 13.8-14.4)
the regulator tells the alt to start pumping out the current. The main point which Phil
misses here the regulator set point is slightly higher than the unloaded fully charged
battery voltage. This "extra" is there to float charge the battery and takes little current
on a fully charged battery. (1 amp or so)
The alt will attempt to the limit of its ablity to maintain the voltage at point #4 such
that no current is drawn from the battery, that is its job. This is where the trouble starts !!

" Your alternator does not directly power your vehicle under normal conditions.
However, if you disconnect your battery while the Jeep is running your FSJ will stay
running as the current that was going to recharge the battery is now dedicated to
running the systems.

This is fact....Look it up if you do not believe it."

Sorry Phil, you can rationalize all you want, fact is under normal conditions current
flow is from the alt to the main fuse panel to power most everything and a small
current though the amp meter back to the battery to maintain its float charge.

"2) The Battery-The battery is the primary source of power to your system. It is drawn
upon by everything whether the vehicle is running or not. It gets recharged by the
alternator(I know, already stated). The battery is a huge reserve cell of electrical
current that is readily available for use by the components needing power. That is
why a battery is capable of producing a lot of amps all at once.
Anybody here have a battery of less than 700CCA? There may be a few but that's
probably because either they, or the DSPO didn't know better. The reason our batteries
are so large is that a large reserve is required to operate all of our systems optimally.
Heck, just starting our rigs requires about 200A (that is the largest single draw our rigs
need at any given time).

Sorry Phil. WRONG "O"

The Battery is there to start your car, and provide some very short term reserve
capacity, for say a transiant load is higher or of shorter duration than the capacity
or responce time of the alternator. Under normal operating conditions the alternator
maintains the system voltage high enough such that no current comes from the battey.
Now as for CCA (Cold Cranking Amps) you seem to confuse this with reserve capacity
that is rated in AH (Amper hours) ,CCA is a indication of how many amps a cold battery
can produce, and is mainly a concern for us that live up here in the north and we need
much greater than 200 Amps to turn over a -30 degree engine with a -30 degree battery.
The AH rating is mainly used for deep cycle type batterys that are ment to be the souce
of power for accessorys like a camper with the engine not running or troling motors on
fishing boats.
Standard batterys are built with CCA, maximizing the surface area of the lead plates,
Deep cycle batterys are built with thicker plates with less surface area and more bulk.
Each charge / discharge cycle takes some lead and standard batterys do not last long
if used (abused) for many cycles.

" Recap-Under normal operating conditions the battery is the main power source for
an automobile and is recharged by the alternator."

Sorry WRONG "O"

Under normal oprating conditions the battery should not see anything but the
float charge comming from the alt.

"

Here's how it goes.....

When the FSJ is not running all power comes from the battery and it has no source of recharge untll the FSJ is running. When the FSJ is started the alternator immediately
recharges the battery and maintains that charge as long as the engine is turning the
alt's pulley. When the battery needs a big charge the ammeter will reflect this by jumping
way to the right for as long as it takes to recharge the battery and slowly come back to
center as the charge levels out. When you turn on an accessory you will notice the
ammeter jump briefly to the right again and slowly return to center as it makes up for the initial draw on the battery. Remember the example I stated above with all the accessories
on? Together they will draw around 80 amps. How can a 60-amp alternator make up for
this? It can't. But, it will make up for 60 amps of it and your ammeter needle will move
to the left to 20 amps which reflects the additional draw of 20 amps on the battery that
is not being made up for. "

YES !! Phil you got the idea. The alt within its limits will attempt to maintain the load !!

<Its getting late so snip some other stuff which is pretty close to being right, I use
my winch for more than a few seconds, and a few other points not worth mentioning>

" Now, when your alt does recharge the battery it still won't overload things as the
battery will not draw the current through the system but rather directly from the
alternator itself."

I think this may be where Phil missed it. Look at crappy ascii art. The only
current path from the alternator is though the amp guage. So there is no
physical way this is going to happen.

" Electricity travels through the path of least resistance and always from a source
of greater potential towards a source of lesser potential."

YES!

"That means that the current will always go directly from the alt to the bat. It will
not take a detour to go through the ammeter first as that is contradictory to physics."

Back to the diagram, WHERE does this happen ?? The only electical path from the
alt to the battery is though the amp meter, to get charge to the batter it has to
go though the amp meter anything else is "contradictory to physics".

"What I have stated is fact. I have the credentials to back up what I say all anyone
has to do is ask. Here are a the electrical formulas that will help you determine how
much is too much."

What you stated is based on something I don't think "fact" is the right word.
I think maybe you need to study the wiring diagram some more.

" I=Current(Amperes), V=Volts, P=Power(Watts), R=Resistance(Ohms)"

Just remeber V=IR and IV=P and derive the rest, memorizing tables is a waste.

To End Cap: Do not swap a large cap alt directly in to a amp-meter equiped FSJ
without addressing where that extra current is going to go. Phil recomends placing
a aux fuse panel next to the battery, that is the worse place for it, as the path to
this load from the alt has only one path to follow and that is though the amp guage !

Mike D.

(Sorry Phil I have any hard feelings just don't like to see anyone toast a FSJ needlessly)
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  #14  
Old 09-24-2002, 04:56 PM
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Crazy_Jeepman Crazy_Jeepman is offline
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Moral of the Story is...............Get rid of the AMP gauge and go Wireless?????
LOL to Technical for me, but yes i alway scrap the Amp gauge. I believe mdill has the FSJ electical down. I have bought enough of them burnt up, and had a couple burn.
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Old 09-24-2002, 11:55 PM
PhilSine PhilSine is offline
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mdill, sorry you had to waste your time giving more false facts. It's too bad you took it personally and if you read all of the posts you will see that the way the system is configured in my FSJ is correct in that no damage will occur from anything I have stated as far as current draw.

I learned about automotive electronics from my father at a young (16) age. He learned from personal experience. He was an Electronics Tech in the Navy fo 8 years and has been on as a civilian 26 years past that. As civilian he was on the Navy's VLS design team where he helped to engineer the Navy's latest missle launching systems. Somehow I doubt he would steer me wrong.

On top of that, I started off installing car stereos for my friends at the age of 16 and was an Electronics Tech in the Coast Guard for 3 of my 4 years of enlistment. I continue in the electronics field today and was at one time employed by a company that specialized in installing the systems that law enforcement vehicles use. That would be all the lights and radios. What I say is correct. Some of what you say is also correct, just not all of it. In the older (pre 75) FSJ's, all roads went through the firewall to the ammeter and back. Later, they changed it as I'm sure they encountered some problems. Now maybe they had it that way in the 75-79 FSJ's as well and the schematics aren't clear about it. Having looked closer at the schematic I can see where I may have mine wired different from the plan but at the same time improved and much safer.

Let this be a lesson to others....

Follow the plan of the 80's and up wiring diagram as it is a better way of wiring. The 75-79 plan is not entirely clear as to what goes where. Attach the alt cable to the same lug on the solenoid as the pos. bat. cable and get your voltage regulator feedback line from the red/white wire in the engine compartment. Changing to a voltmeter is not a bad idea but I will stay with the ammeter for now.
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Old 09-25-2002, 12:41 AM
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Crazy_Jeepman Crazy_Jeepman is offline
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UH OH another exhaust topic, or is it exhausting topic? Oh well no worries. My advise is most of us here have no clue what this all means.
I=Current(Amperes), V=Volts, P=Power(Watts), R=Resistance(Ohms)

Power...
IxV=P
I2xR=P (I2=I Squared)
V2/R=P (V2=V Squared)

Current...
square root P/R=I
P/V=I
V/R=I

Volts...
sq. rt. PxR=V
P/I=V
IxR=V

Resistance...
P/I2=R
V2/P=R
V/I=R

However EVERYONE here can relate to seat of the pants hands on experience type of knowledge of these rigs. The wiring burnt burnt by an amp gauge is nothing new. I have sold many wiring harnesses and instrument cluster to repair burnt ones. It all comes down to Original Recipe or Extra Crispy
AMP Gauge Facts #1
AMP Gauge Facts #2
AMP Gauge Facts #3
AMP Gauge Facts #4
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Old 09-25-2002, 12:51 AM
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Guy walked into a bar and said......
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Old 09-25-2002, 12:56 AM
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BUY ME A BEER??
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Old 09-25-2002, 01:02 AM
Jeeptruck Jeeptruck is offline
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wow, just read all that and still don't know waht to do. my biggest fear is a ammeter fire or melt down what is the best way to avoid a fire a losing the truck? please help so i can walk into the store/ house and not look back to see if my truck is on fire
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Old 09-25-2002, 01:10 AM
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Go with the FORCE and Allstate Insurance if you keep the Amp Meter. LOL You might be in good hands!!!
Up to you, Good and Bad info is available. I might add I have a few harnesses and dash parts left.
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