Shorting voltage regulator?? Maybe??

[Jon Powell]

I tried looking for this, but couldnt find anything, so I am asking all you intelligent Z heads for some help.

I purchased a 1977 280Z and was told that the battery is going bad, might need to be replaced. I started doing some work to the car(brake lights, headlights, horn wiring was all bad) and noticed that whenever power is supplied to the car(hooking up the battery) the voltage regulator clicked, creating a draw on the system, draining the battery.

I traced it down to the yellow wire going from the alternator to the battery and found that if I unplug the white plug from the alternator with 2 pins place like this: --| it shuts off the regulator. the voltage regulator LOOKS like its fairly new though so I dont suspect that it is the problem.

First question is, what does the yellow wire go to, if anything, besides the voltage regulator?

Second, does it sound like the alternator could be causing the problem?

Thanks in advance, and sorry for rambling on so long.

Jon Powell

[Jon Powell]

Come on people, help a brother out!!!

[ChrisA]

I traced it down to the yellow wire going from the alternator to the battery

Hey John, I'm not real familiar with 280Z wiring but I didnt think there was supposed to be a wire from the alternator to the battery.

On a 240Z, there is the main wire to the amp gauge, and a two wire connection to the voltage regulator.

You have a volt gauge instead of amps but yours should be the same. You said the wire goes from alt to batt, but then you asked if the yellow wire goes somewhere other than the regulator. Where exactly does this yellow wire start and stop right now?

The regulator could be bad even though it looks new.

I'm stumped as to why it clicks when you hook up the battery. I have a 280Z manual at home, I'll look at it tonight and see what I can find.

Chris

[Jon Powell]

It appears to be from the alternator to the regulator. I typed battery by mistake. It seems to be activating the regulator as soon as the power is applied to the system.

Thanks for taking the time to help, I appreciate it!

[ChrisA]

Hey John, do have any salvage cars near you? Cheaper test than buying a new regulator right away. If a used one clicks then we're back to square one.

I may be all wrong on this, but I once read somewhere that the electronic voltage regulators sold at the auto parts stores arent worth a damn. Its best to get one like the originals that had the twin relays in them.

I'll keep checking things for you.

Chris

[Jon Powell]

I was thiking also of just upgrading to a '78 alternator with the internal regulator...

Most of the junkyards here in NY have rusty junk buckets. Nothing worth a damn.

Thanks for the help!

[ChrisA]

I was thiking also of just upgrading to a '78 alternator with the internal regulator..

Very good idea John. Been done to many a Z car. I have the parts to do it, just not the time. :ogre:

Chris