Hey Everybody. Mind if I sneak back into the clubhouse?
Been buried under life's relentless realities for the last 18 months or so, and 914s were by necessity out of the picture for a while. It feels good to be back and see many of the same standby names still active here.
The clouds have parted a bit, and I dusted off the 8 a couple weeks ago only to remember it had a charging problem when I parked it. I turn a wrench pretty well, but electrical issues make my brain hurt. I'm hoping somebody can offer some ideas.
The car has had charging issues since I bought it. Now that I have had the alternator rebuilt for the third time in 5 years, I'm pretty sure that is a symptom and not a cause of the trouble. In trying to reason it through (unsuccessfully), I have noted or found the following:
1) Since the day I got the car, I noticed that when the turn signals are on, or when I step on the brakes (light the lamps), I could hear the fuel pump slow down accordingly. I always attributed that to a weak ground somewhere. Later I installed a volt meter in the car, and I see a temporary drop off of a volt or 2 when either of those things are things are on.
2) With the car off, if I check the voltage at the output pole of the alternator (or anywhere), the voltage is about 12.5. If I turn the key on, but don't start the car, the voltage at the alt. pole drops to 3-8 volts. It stays 12.5ish anywhere else. When I start the car, the alt. output does not go up (fresh alt rebuild).
3) The alternator on the V8 only has one input, and that's the indicator light wire. If I disconnect that wire, the voltage doesn't drop at the output pole when I turn the key on. Key on, the voltage in the disconnected indicator wire is 12.5, but I have found that if I connect a test light to a hot, w/ key on, the indicator light wire will light the light (i.e. function as a ground also). Seems to me that points to a short, but I don't know. That's when my brain begins to ache.
4) I disconnected the main ground points under the dash and in the engine compartment for cleaning, and found that even with them both off, the dash cluster still functioned normally. My 3rd grader level ability to read a wiring diagram seems to say the cluster shouldn't work with those disconnected, but it did. More proof of a short?
John built a great car mechanically, but wiring looked not to be his forte. Under the dash is more than a little bit of a diy cluster fark, and starting over would be a serious effort. I'm hoping one of you guys can help me efficiently sort this out. Otherwise, she may get parked for another extended spell. That would bring me down.