[shepardb]

I have a 1981 Chevy 4X4 3/4 ton with a 1 ton suspension. It has a 350 4 bolt main and a TH350. The problem that I have is that it will not charge the battery. It will not drain the battery when running. I changed the alternator, battery, and all cables. I got a used engine harness. I also unhooked the wireing harness at the firewall except for the part for the engine. Rebolted all the grounds. Pulled off the tape holding together the harness under the dash. No burns or frays. Everything works find, lights, wiper, lighter. I also took out all the fuses. Nothing has even gotten close to helping. Am I missing something? Can someone help.

[shepardb]

Can no onehelp? Do I need to put this in the advanced section?

[poncho62]

While it is running, are you getting 14+ volts at the alternator and the battery?

If you are getting it at the alternator and not the battery, you have a wiring problem. If you don't get it at either, you still have a problem at the alternator. Is your belt in good shape? If it is slipping, it may not charge enough.

[shepardb]

WHile the battery cable is hooked up, I get less than 12V. If I unhook the battery, viltage jumps to 14+ volts. Truck also has new battery.

[shepardb]

I bought a new switch so I could isolate EVERYTHING. The only thins that is hooked up now is the battery, switch, alt, starter, distributor, and all new wires. This bypasses everything. Still no difference. Is there any way that the sistributor is causing the proble?

[jmhollis]

With everything off, is the battery voltage staying at 12V? If the engine is off and you turn the headlights on for 3 or 4 minutes, is the battery voltage still at 12? If not you may have a shorted cell in the battery (even a new one). Find a friend and swap batteries for a check and see if the voltage problem follows the battery.

If this shows the problem to be in the vehicle, you probably have a bad internal regulator in the alternator. If you have an amp meter in the dash (not a voltmeter), there is a slim chance it could be part of the problem.

Let us know what you find.

[Kevin45]

It could possibly be the amp meter. Do you have to jump the battery every day or is it just not showing that it is charging on the meter? If you never have to jump it and the battery is staying charged I would replace the gauge with either a new one or try one from a junkyard.

WHile the battery cable is hooked up, I get less than 12V. If I unhook the battery, viltage jumps to 14+ volts. Truck also has new battery.

I am assuming that you are doing this while the vehicle is not running. If it goes from 14 to 12 just by putting the cable back on then you have current draw somewhere. Either thru a stereo, clock, amplifier, or something that is hooked directly to a hot line. I would try popping the fuses and replace them one at a time until you find where the current draw is coming from.

Kevin