stock alternator burns brushes

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The shunt is part of the ammeter gauge. You can bridge the terminals on the back, or you can move one ring terminal to the other side. Your gauge will no longer work.
I suppose for testing purposes, you could wire in a 12ga jumper, somewhere else, going around the gauge; on account of it being a real PITA to pull the dash-console out. You would need to go from the battery to the ballast resistor feed. This will energize everything on the Run circuit, going back to the sw. Everything will work like normal, except the car will not shut off until the jumper is un-clipped. Turn on everything electrical including the 4-ways, and record the charge voltage on the battery with the engine idling. Then shut everything off including removing the jumper. And test the battery REST voltage, which should be no lower than perhaps 1 to 1.5 volts less than the recorded charge voltage. This assumes the battery was fully charged at the start of the test.
If this test shows everything is in order, NOW it's time to pull the cluster (battery disconnected), and bypass or replace the ammeter. If you decide to bypass it, you will probably want to install a voltmeter somewhere in the cab,permanently.
 
67Dart273 said:
This overcharging (over voltage) IS ALMOST ALWAYS due to either voltage drop in the harness or ground path voltage drop between regulator and battery. I've posted on this hundreds of times

In rare cases this is caused by the regulator, and also rare is a battery going bad

To test for harness/ ground voltage drop:

1....Turn the key to "run" with engine stopped. Hook your voltmeter as close as you can get to the bulkhead feedthrough the "ignition run." This connect to, amoung other things, the VR blue, the alternator blue, and the key side of the ballast resistor

hook your other probe to the POS battery post. You are hoping for a very low voltage, the lower the better. More than about .3V (3/10 of one volt) means you need to start looking

The functional path for the VR blue wire voltage is Battery........starter relay stud.........fuse link.......bulkhead connector.......ammeter (RED)........through the ammeter........out on BLACK........to the welded splice........branch off to IGNITION SWITCH connector.........through the switch.........back out the switch connector on blue "ignition run"......out the bulkhead through the firewall...........and to the under hood ignition loads.

ANY OF THOSE POINTS can and will cause drop

2...GROUND...........run this test with engine running at "low cruise" first with all loads off and again with lights, heater, etc running

Stab one probe directly into the mounting flange of the voltage regulator..........Stab the other into the battery NEG. Again you are looking for a very low voltage, zero is perfect, the lower the better.
Click to expand...
Thanks for all your help , youre the one with the most insight on this subject(no offence to others,and I thank all too)but I found the answer in some other search ,link: overcharging the battery HELP

You are the one that proposed tests in that post and I followed your procedure and right after pulling the green wire at alt field connector I got my answer , bad alternator , so returning it tomorow and hoping I get a good one this time , again for everybodys sake never assume a new part is good , thanks for all your advice(I was really starting to wonder if I was testing all circuits properly)Thanks again to all and will post results soon!
 
Got new alt. today , bolted it on and went to our local cruise night , got a bit of rain came back gassed car up , all is good , thanks again to all that piched in here , all been great help and hope this post will help others in future.
 
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