Charging problem - Part II

[440roadrunner]

Still have about 11.7-.9 on the interior gauge,my ammeter displays a slight "discharge" but I don't seem to be drastically draining the battery when driving. Tried the "jumper" one more time after replacing and repairing the other wires,and got the same result. After a short amount of running time,the voltage climbed when revved to 16. Went back to about 12.2-.3 at idle.

AR67GTX;please don't think I hijacked your thread. Your problem was eerily similar to mine;hopefully,we all benefited. Electrical issues (almost) make me want to start drinking again. NOOOOOOO!!!!!!!

Refresh my memory on what you did with the jumper

The low voltage in the interior seems related

The main causes of overvoltage are

(rare) bad battery with bad cell

poor ignition voltage to regulator IGN terminal

poor regulator ground

bad regulator

1---To check the regulator ground, Start and run the engine, and monitor battery voltage. You want the voltage above 13, but try not to run it at 16 more than long enough to check this out. Adjust the idle screw/ fast idle to get the engine speed up some

2---Now set your meter on low DC volts, and stab one meter probe directly into the battery neg. post. Stab the other probe into the regulator mounting flange. You should read virtually ZERO, or only just a couple of tenths of one volt. Anything more means a poor ground between battery, engine, body, and regulator.

3---Next see if the regulator is getting ignition voltage. To do that, turn the key to "run" but with engine OFF.

If you have breaker points ignition, first make sure the points are Closed. to do that, hook your meter from coil NEG to ground. Battery voltage means points are open, a few tenths of a volt means they are closed. Bump the engine if necessary to close them. THIS IS TO put a load on the IGN buss

With meter now set to low DC volts, hook one probe to the battery positive, IE starter relay big stud.

On 69/ earlier systems, hook the other probe to the regulator IGN terminal -- the push on one

On 70/ later systems, either hook to the "key" side of the ballast, or to the blue field wire on the alternator. Do not disconnect it, back probe the connection

You are HOPING to read a very LOW voltage, not more than .3V or so, that's 3 TENTHS of one volt

With your low reading on the interior voltmeter, I'd bet this reading is more than a volt OR TWO.

THIS VOLTAGE (harness drop) adds itself to the regulator setpoint, and causes the battery to overcharge. (overvoltage)

 

[AR67GTX]

Problem solved

Here is a tip for trouble shooting for those of us electrically challenged. Hang on to your old, still functional parts. I finally dug out the old aftermarket, chromed box voltage regulator I took off the car about 8 or 9 years ago and installed it in place of the solid state VR I put in it back then.

Presto - voltage and charging problem solved. The engine is cranking out around 14.5 volts and the ammeter gage is showing a charge condition. I guess I'll bite the bullet and get the Echlin VR 1001 unit since I don't have any ideal how long this other one will last.