63 ammeter problem

[Mel H.]

I've searched archives and didnt see anything specific to this problem. Ammeter gauge on '63 340 quit about year ago. I recently replaced with new one, but now it reads backwards.

That is, when I turn on lights, needle leans to right (+) instead of left (-). And with engine running and charging, needle leans left (-) instead of right (+). Acts like its hooked up backwards....but I've checked and double checked connector on back of gauge and all looks correct, with black wire to outside. In fact, dont think this connector can be hooked up backwards.

Anyone have any ideas/suggestions?

Mel

[Michael G.]

Re: 63 ammeter problem

I had the same problem a year ago. Turned out to be an issue with the repop harness. Replaced the harness, problem went away. Never did figure out exactly what was wrong. Could have been a harness problem, or a ground problem, though I tried to eliminate connection issues by cleaning and reinstalling all the connections before I gave up and replaced the harness.

I tested the system first by plugging in a known good gauge one from my other car. The good one also read in reverse with that repop harness.

If you can find a good gauge, you may want to save a LOT of testing by just plugging it in to the gauge plug on your car without installing it in the dash. If you then just turn on the lights, without the key on, it should show a discharge. If it does, your gauge in the dash has reversed polarity (maybe internal to the gauge). If you see a charge, it probably means you either have a connection loose or corroded, or a bad harness. Good luck

[Duke W.]

Re: 63 ammeter problem

The ammeter is really a voltmeter that uses the slight voltage difference at two points in the system as a surrogate for battery current, so it sounds to me like reversing the wires at the ammeter connector will solve the problem.

Duke

[William C.]

Re: 63 ammeter problem

You and I have the same take on it, repop wiring harness build misplugged either at the firewall or at the gauge. Original fixtures electrically checked for problems of this nature, but with a reproduntion, it's anybody's guess.

[Michael G.]

Re: 63 ammeter problem

I actually took the wiring harness off of my other car and put it on the one with the problem. The problem went away. I then put the repop back on and the problem came back. Funny thing was, the repop had all the right color wires in the proper sockets in the dash plug, but it acted like they were crossed. Supplier replaced the harness and all was well.

[Mel H.]

Re: 63 ammeter problem

Thnx for the ideas, guys. Makes sense. I'll try another gauge as thats pretty simple.. if same problem, I'll switch the wires at the connector and see what happens.

As noted, electrical stuff can present unexplained goblins at times. Regardless, these are some good ideas to try and I appreciate the tips.