When my car is on idle and I have the lights on they don't have a steady light. They sort of dim down a little and come back again. This goes on the whole time.

Is this a problem with the voltage regulator?


Jan

It very well could be. Also, those old 60s vintage electrical systems weren't the best design. Power for the headlights must travel through the firewall, through the switch, and back out to the headlights. I say this because someone here recently recommended installing a head light relay.

The old light circuit energizes the relay coils and the relay contacts provide a high current supply from the B+ junction or horn relay.

But you are probably right - the regulator (or alternator) isn't keeping up with the load at idle. I believe the regulator may be adjustable - I haven't fooled with the mechanical regulators enough to know.

Another area to investigate is the wire that connects from the B+ junction behind the battery to the horn relay and alternator. It could stand to be larger and have fresh clean connections.

Take a volt meter and connect the ground lead to ground near the battery. Then measure the voltage at the regulator while repeating the dim light test. Then move the meter probe through the circuit (such as battery, B+ junction, head lamp circuit, etc.) to make sure the problem isn't simply a bad connection. I'm sure there are several things you could do to improve the situation, but alternator / regulator is near the top of the list.

-dnult

I would start with a electronic and not mechanical voltage regulator. It's cheap and easy to replace. I painted mine black to match the original. I assume the Wells VR715 part number is the same for 67-69.

Make sure you mount and ground the unit before connecting the plug.

I got fed up with the whole external regulated thing and swaped in a 78 amp 12 SI that is internally regulated. My thought was why spend $20 to $40 to keep putting a patch on inferior technology. For $59.99 for the life-time guarantee alternator and another $20.00 for some plug in connections. The same can be done by cutting and splicing a few wires for very little cost as well. I talked about it in another thread a couple days ago. I say run the tests and see if the problem is either the alternator or voltage regulator (chances are it is). If it is think about the upgrade. I got the plugs from M & H at www.wiringharness.com (http://www.wiringharness.com) For some good info on the whole charging system check out www.madelectrical.com (http://www.madelectrical.com) Lots of good reading.