Check out of charging system

[patrickt]

There are five wires coming out of the harness to the voltage regulator. Four go to the plug and the solid black one has an eyelet for the ground to the regulator itself. Using your VOM, do this:

1) Place the + lead of the VOM on the positive side of your car's battery and the - lead of your VOM on the black eyelet. Do you have 12 volts? If not, there's a bad ground connection to the black wire.

2) With the key turned on, but not cranking, put the + lead of your VOM on the YELLOW/RED wire going to the voltage regulator and the - lead of your VOM on the black wire's eyelet. Do you have 12 volts?

3) If the answer to #2 was "No" then, just for the heck of it, turn your turn signals on, each way, and see if that makes the voltage go up and down on the YELLOW/RED wire like a flashing bulb would do. BTW, this should never happen.

Then report back.

[DanEC]

Alas - my luck with fixing the turn signals did not hold true for the charging problem. New regulator and bench tested the alternator (OK) and still no charge.

Going to start over with testing again. Any other suggestions are welcome.

Dan

[patrickt]

If the alternator checked out, and the VR is not broken, check the continuity of the field and stator wires running between the VR and the alternator, and check the continuity of the the orange wire running from the alternator to the fuseblock. Then double check the grounds to both the alternator and the VR and, if all of that checks out, and the connections are tight, then it is metaphysically impossible for the system not to charge.

[DanEC]

Everything seems to check out but it doesn't charge. Jumpering across the VR terminals and checking the voltage from the + starter relay to the neg battery cable I get 14.5 volts at idle. Ammeter is pegged. Plug the VR in and I get 12.5 volts throughout the the system and a slight discharge from the distributor I guess.

I put my VOM in the VR jumper circuit and got 12.4 volts is all. No change when reved up.

I ran continuity on all the wires and all passed. I checked all the grounds and they test good to the engine.

Seems strange that with the VR jumpered I'm getting 14.5 volts at the starter relay but only 12.4 volts between the yellow and blue wires in the VR plug.

My battery was down to about 50% so I put the charger on it. That's about my last hope - maybe it's just too low to charge somehow.

[patrickt]

Tell me if this is exactly what you are doing, since sometimes posting on a thread can be misunderstood:

When my VOM is place on my battery, with the car off, it reads about 12.7 volts. If I leave the VOM on my battery, and start the car, while it is running the voltage is still about 12.7 volts.

With the VOM still on my battery, if I unplug the connector to the voltage regulator, and jumper across the first and third tang, and leave the plug out of the voltage regulator, when I start the car and rev it to about 1500RPM I get over 14 volts.

Is that exactly right?

[DanEC]

Originally Posted by patrickt

Tell me if this is exactly what you are doing, since sometimes posting on a thread can be misunderstood:

When my VOM is place on my battery, with the car off, it reads about 12.7 volts. If I leave the VOM on my battery, and start the car, while it is running the voltage is still about 12.7 volts.

I got 12.9 volts at battery at rest (charger had been on) and 12.6 volts when I started it. The ignition light is on and my ammeter is showing a small discharge.

With the VOM still on my battery, if I unplug the connector to the voltage regulator, and jumper across the first and third tang, and leave the plug out of the voltage regulator, when I start the car and rev it to about 1500RPM I get over 14 volts.

I have about 13.5 volts at idle and it will go up to 16 or 17 as I rev it up.
Is that exactly right?

Pretty much the same - I just can't get a charge on my gage or the light to go out.

[patrickt]

Originally Posted by DanEC

Pretty much the same - I just can't get a charge on my gage or the light to go out.

Then you've either run in to two bad voltage regulators, or what is more likely, is that the voltage regulator is not getting excited in to functioning via the small charge through the filament of the dashboard light. Make the test changes, as per my Post #4 in this thread, and see if your system then charges properly. If it does, then the problem is the excitation feed to the voltage regulator. You can take your time on fixing that. If your dashboard light is still on after making the modifications I outlined, then you have miswired the light and that is the problem.