Volt meter and tach issues

[datsunson]

I have a 77 280z that has had electrical problems since I got the thing. I believe I've got pretty much everything figured out and I'm ready to start driving it. But I'm not sure about the volt meter. I've got 3 questions...

1) The volt meter reads 12v when the car is off and no lights on. Is this normal, or is something staying on and draining the battery?

2) When the car is running, I've got 12v, but the red charge light stays on. What should I be looking for?

3) And last, my tach jumps all over the place when accelerating or above 4k.

[leftover z]

The volt meter stays on all the time, and should read 12 volts. With the car running, it should read about 13.8 volts. The red charge light indicates a problem. I'd check your battery and alternator. Regarding the tach, it could malfunction if you are not getting a full 12 volts. Take care of your battery & alternator first. If the tach is still messed up, I'd check all your connections. They tend to corrode after 30 + years.

[datsunson]

I just spent $90 on a new battery, so that shouldn't be it. The wiring for the alternator was screwed up, so I'll take a look at that and get back. But to be sure, the charge light on the vlotmeter means that the battery is not being recharged by the alternator and will eventually die? Is that correct?

[leftover z]

Yes, the light indicates your battery is below 12 volts and NOT being charged. The Z won't run when the volts gets down to 9 or 10 volts.

[datsunson]

Replaced the alternator and voltage regulator and no charge light! Thank you! I was going to replace the belt as well but wasn't sure how to get the thing off. I looked in the service manual and is just said to replace it. No steps on removing. Do you have take off the fan shroud and fan?

[leftover z]

Didn't you remove the belt when you replaced the alternator? You shouldn't have to take the fan or shroud off. It can be tricky but it can be done.

[leftover z]

What service manual are you referencing to? If it's Haynes or Chiltons etc, they aren't much help. If you don't have the FSM manual, you can download it for free: http://www.xenons30.com/reference.html