$15 Ammeter/Voltmeter Retrofit write-up

[bvibert]

Originally posted by Heimeken:
Excellent, best tech post I've seen in long time. Thanks.

Definitely, I'd say its suitable for the archives...

[2manywags]

Did this conversion on my 82 today. Thanks for the post!

[Boghog1]

Just finished this and It looks great, I mounted mine slightly higher so the blue line is not as visible and raised it off the bracket by the thickness of the paper washer and it sits at the same level as the ammeter. I had to add wings from the bezel that I cut the word volt out of because you could see just ever so slightly behind it. Thanks for the great write up!!!

[shimniok]

That's friggin awesome!

[Headhoncho]

I was bored and ran across this sticky at the perfect time. I just installed a Taurus fan and a 95 amp alternator to my truck. I was in fear of frying my amp gauge (which I have never been a fan of) so I picked up this volt gauge for 12.99 at Autozone and went to town. I followed the instructions and now I have a great looking and funtional new volts gauge. I also ran a 10 awg jumper direct from the alternator to the + side of the soleniod just for added insurance. Also, while I had the instrument bezel apart I checked/replaced bulbs and cleaned all copper surfaces. I have dash lights I never knew I had before!!!

Thanks again for the R&D. Much appreciated.


JR

[serehill]

WOW A long way since 2005.

Sometimes fact is better than opinion or theory. The fact this is documented and this does happen. I've seen it with my own eyes. More than once. For Many different reasons not one.Fact is these ammeter systems have other issues but to say it's unknown or doesn't happen or not not worthy are statements the victims would not really appreciate.
My experience:
Back in the mid 80's I was off roading with a few guys & one radioed (on CB) he was stuck. A J-10 when we got there he was winching his way out with a 12 K winch he was cycling the winch by using it until the battery got low & then taking a break when the battery would get low. He was outside the truck using his remote when smoke started rolling out of the cab then from under the hood as the wiring started burning. He stopped winching & dumped his entire extinguisher on an electrical fire. If you don't know as long as the short or overload is still going on the extinguisher won't stop it. By this time the engine compartment was on fire. By the time he got the hood open & cut the battery cable it was burning to the ground. Being in a mud hole slowed response down. It definitely does happen.
You Know AMC, Dodge with similar system both recommended you never charge a completely dead battery because of this by running the vehicle.
News flash AMC had crappy wiring systems. Just because it hasn't happened to you doesn't mean it doesn't happen.
Modified electrical systems are more susceptible to this. Lots of reasons it can happen Not just the one described. We've seen threads where folks that believed it doesn't happen became victims.
I believe in fusing but there is a problem. Most of these burns are simply because the circuit can not provide a large load long term. It should have to sometimes is the thought but some times it can. Usually when t does get into the short or long term charge it is not controllable. The alternator is 50 to 60 amps putting a fuse too small that would actually protect it would have a tendency to blow at the most inopportune times. Remember they have fusible links when this happens. The fuse would be redundant. Unless some one has removed them. You do need to protect the circuit but it's not the end all cure.
Putting a low amp fuse in place means it will blow in large charging situation and you lose the charging loop. Not acceptable. The battery quits charging. Merely a bandaid on a bullet wound from one problem to another.

Yes no doubt these are sometimes flukie incidenes. There are no vehicles built like this today this would be possible on. For good reason. So as in Dirty Harry How about it do you feel lucky?

Yes I understand there are the voltmeter impaired that can not read or don't like to read them. With nothing but commercial vehicles that have ammeter now days how do you operate a late model vehicle they all have voltmeters? BTW commercial vehicle ammeters are noting like these they use a shunt style ammeters because the series meter doesn't work for them either. The jeep style ammeter was the cheapest way to do it but history proved they simply were not worth the liability.
A solution can be made with a shunted ammeter also that will yield the same results.

a couple of caveats:
Cost of the shunt system can be distressing for a good one. They don't have one that will fit in the dash cluster.



Real bottom line is not everyone is an electrical guru so telling folks no worries can be a problem. Lowest risk is the target. Less risk some risk is not.
Another totally unrelated subject on the later models. The choke circuit is not fused on the carburetor. If it comes into contact with the ground it can burn the rig to the ground.

I won't be the one to say oh that won't happen to you.

If it happens at all it happens.
What is also true beside a short are the variables of the short. The variations on that theme if you will. Also other real issues that can create the burn.
Shorted diode in the alternator.
Alternator failure that causes an open circuit. Opposite of a short. The battery to send power back through the ammeter to try & run the vehicle. The alternator is most likely to fail under high load. If the alternator fails & the system back feeds to provided power while you're driving at night with the lights and a/c on this becomes a very real possibility. There are another possibilities like winches added loads ETC. It's not limited to one thing. Not to mention its 50 year old technology & 40 year old wiring. I'm sure victims have several scenarios.

I did the volt ammeter swap on mine years ago one digital on the Cherokee. One analog like this one on my Honcho but a little different. This mod is a great start but not complete in my opinion.
I disconnected the red & yellow from the ammeter and cut and capped the red under the dash at the ammeter.
I moved the red wire from the alternator to the starter solenoid via a 40 amp circuit breaker. The commercial auto reset kind not the plastic stereo junk. Then I took the yellow through a 40 amp circuit breaker also & ran it to a new fuse block I added inside for brand new circuits. The I ran a #2 from the alternator to the starter solenoid & now the circuit charges from the alternator right to the battery.
Like almost every automotive manufacturer in the world it connects like a modern vehicle.
The red still runs the old electrical it always ran.
The charging loop no longer runs all the way to the ammeter & back to the battery. It no longer depends on a wire the size of a fishing line in the ammeter to run a possible 60 amps.
I tied the voltmeter into the ignition switch so it only works when the vehicle is operating.








For those that say this is not an issue & have not seen history on this.

For the record the Dodge ammeter is exactly like the jeep. Apples to Apples.

http://www.madelectrical.com/electricaltech/amp-gauges.shtml