Hello all,

I have a strange issue with my '73 2.0. The charging system is just not working right. During the day I notice the voltmeter starting out at about 14vt, but as I continue to drive the car the voltage reading will drop. If I drive the car at night, the charging system can not keep up with the lights. Lights are nothing special, auto store halogen sealed beam. I don't use my fog lights as it really drops. If I go out the day after driving at night the car will barely turn over the battery is so run down.

The generator light does not glow while the car is running. It's on, of course, when I turn the key on but goes out after it starts like normal.

Do I have a voltage regulator issue here? Any thoughts would be appreciated.

Tom

Check the easiest simplest things first. Is the alternator belt tension correct? Ground wires and contacts clean and uncorroded? Start there.

Voltage regulator on the relay board!

As well as what is mentioned above, you may want to go to sears and get a load test on your battery...it may not be running at full power.

Rich

I'm guessing you lost a diode in your main rectifier bridge in your alternator. With one diode out, you'd lose a third of your output. The fact that it does OK in the daytime, voltage wise, suggests your regulator is OK. Not 100% for sure, but seems that way to me.

Mine did this, 25 years ago, and I continued to drive it (daytime only) for some time. When I finally pulled it and looked inside, the wire braid on one of the diodes had melted and opened up.

Jim

Just a little tip I figured out the hard way. When the vr is starting to fail, you can actually see the voltage kinda switch high and low real fast. The inside gauge can't pick it up, but my megasquirt sure did, so did my old Simpson analog volt meter. My fluke dvm would pick it up on the rms bar graph, but not on the actual reading. Two days after noticing it, blam, charge light went on.

Thank you guys for your ideas, I'll certainly use them when I check this out.

I will be checking all the grounds first, then...VR. If not that, then I guess the alt will need to come out. Not looking forward to that job!

Thx
Tom