C1 Battery Not Charging

[Peter S.]

My battery is not charging. I removed the generator (original, but rebuilt 3 years ago) and had it tested. It tested fine, in fact the shop said it was the strongest 12v generator he had tested (it was putting out 30 amps).

I suspected the (original) voltage regulator and replaced it with a new one from Lectric Limited. It looked pretty much like the old one, and I replaced the generator harness wire just in case. The behavior after replacing these things was exactly the same as with the old voltage regulator.

I polarized the generator by shorting the bottom two connections on the voltage regulator, and got the expected spark.

Trouble is, my battery is still not charging. If I charge it on the charger, then drive for 30 minutes, I come back and the battery voltage is low, say 12.5v versus 13.5-ish when it is fully charged. It seems like the spark is running off of the battery. If I drive for an hour eventually the engine starts running bad because of no juice to the coil I assume.

The Ammeter does not go above zero. If I turn on the lights or step on the brake, the ammeter goes negative but I never see it go in positive territory.

Could the starter solenoid cause this if it's not going back where it belongs after starting? Or what else should I look at?

[Joe M.]

Re: C1 Battery Not Charging

What type of battery are you using?

[Peter S.]

Re: C1 Battery Not Charging

What type of battery are you using?

It's just a regular lead-acid car battery, not a very large one. I ordered a reproduction battery but I've been waiting for a long time.

[Dan D.]

Re: C1 Battery Not Charging

Try grounding the field terminal on the generator. That should cause the generator to put out full current. But do not ground the armature terminal. That will tell you if the generator is working, and if your trouble is downstream from the generator.

-Dan-

[Peter S.]

Re: C1 Battery Not Charging

I tried grounding the field terminal. I connected it to the negative post on the battery with a jumper cable. I didn't see any difference -- I had the headlights on, they did not get brighter and the ammeter was still showing a bit in the negative. What else can I take a look at?

[Dan D.]

Re: C1 Battery Not Charging

Okay Pete, the next step is to look at the armature terminal of the generator with a voltmeter while you ground the field terminal. When you do this, the voltage at the armature terminal should go very high - 15 volts or so. If it does, then the generator is working and your problem is with the voltage regulator. If the armature voltage does not increase when you do this, then the generator is not working. This assumes of course that the wiring is all okay.

-Dan-

[Peter S.]

Re: C1 Battery Not Charging

Here are my voltages:
Generator terminals at idle without FLD grounded = 10.6V
Generator terminals at idle with FLD grounded = 15.1V
Battery, key off = 12.55V
Battery, at idle = 12.62V

What should I look at next?

[John P.]

Re: C1 Battery Not Charging

Hello Peter, Make sure you have a good ground at the regulator. Being it is mounted on the fiberglass inner panel, it requires a separate ground wire to the outside mount base. John

[Richard M.]

Re: C1 Battery Not Charging

Strange that we he grounded the Field the first time it didn't show a change, then the second time it did. Since it's 15V now at idle with F grounded it appears the Regulator or harness is faulty. Good idea to check ground too as that will affect operation.

For reference, another way to test the generator is to motor it. Remove the belt and harness connections. Connect Bat+ to the Armature terminal, Ground to the generator case(which will be default by the mount bolts, just make sure your battery Neg is connected), then ground the Field terminal. The generator will run as a motor. Connecting a Ammeter in the circuit will yield condition. The Pass car manual has the current spec.

[Thomas H.]

Re: C1 Battery Not Charging

Wouldn't be the first time I saw a "new" regulator bad out of the box.

A few years back I got one of those LL regulators for my 60. Still had charging issues. Spent hours troubleshooting. Finally went to the local NAPA and got a regulator through them. Everything worked fine with that regulator.......

A good point was made earlier about having a good ground from the regulator to the generator. The harness should have a braid wire that connects the generator to the regulator. You mention you changed the harness, so you may want to revisit that connection.

Tom

[Peter S.]

Re: C1 Battery Not Charging

I put a jumper from the negative on the battery to the chassis of the voltage regulator, and my ammeter shows in the positive. If I turn on the headlights, it now shows about zero, where before it showed in the negative quite a bit. So the ground seems to be the problem. The harness to the VR from the generator is attached to the screw on the top of the VR cover (per the diagram) so I'm guessing that's the problem, too much paint or something? I'll try to scrape paint off both ends of the harness ground braid where it attaches to the generator and the VR, but presumably the generator case is a good ground.

If I read that from the generator ground bolt to the battery negative with the engine off it is 0.3 ohms.

Does anyone think I need to throttle up the VR voltage a little?

[Thomas H.]

Re: C1 Battery Not Charging

If I read that from the generator ground bolt to the battery negative with the engine off it is 0.3 ohms.

You need to measure from the regulator bare metal frame, to the battery - terminal. That should be as low as the generator to the battery - terminal.

The harness on my 58 has a braid that runs from the top cover screw to the generator. I just installed it today after finding the right date coded regulator. Also had it tested with my generator at a local motor repair shop, but I digress.....

I believe later model year regulators used a screw directly into the metal frame of the regulator for the ground wire from the generator. Either way, like you suggested, make sure you are getting good metal to metal contact - no paint in the way at either end.
Tom

[James O.]

Re: C1 Battery Not Charging

On my 1959, I found it difficult to get a good ground from that little braided shield that attaches under the screw on the painted voltage regulator cover that goes to the case of the generator. I left that alone for correct look but I cheated and made a short 5" jumper (12 Ga.) with an eye terminal on each end and went from the bolt that holds the regulator case (not the cover) to the fender well with the other end to a frame bolt that was close by. No one can see it. Try first with a booster cable to verify that will solve your problem. I bet it will charge like crazy.

[Dan D.]

Re: C1 Battery Not Charging

Pete, unless you are having your car judged, I would connect the voltage regulator ground braid to one of the regulator case mounting holes - not the cover screw. The cover screw requires the screw to carry the ground current, which is never good, but glad you found your problem.

-Dan-