76 possible electrical problem

[5thhorsemann]

Your Alt is full feilding and overloading the radio, 17V at the battery will cause more and more problems as time goes on. I would upgrade to the internally regulated alt. although I don't know if it's the same as upgrading the 240Z, but it solved a host of electrical issues when I changed mine over.

[Zed Head]

The extra voltage could be overloading your ignition module also, causing it to die then able to restart after 30 minutes. It will probably die for good if you don't fix the voltage regulation. The specs are in the FSM but anything over 15.5 volts is too high, I think.

You have a problem with voltage regulation.

[bhermes]

OK. So a little more learning. Is it the job of the volage regulator to regulate the voltage. In otherwords if the alternator is full fielding shouldn't the voltage regulator drop the voltage down suppleid to the battery. Maybe the incorrect voltage regulator was installed.

Comments.

Again, thanks for all the help. I am beginning to think I am going to make it to work more than 3 weeks in a row without walking.

[5thhorsemann]

Yes, the regulator is the problem.

[rcb280z]

I had a similar problem a few years back in my 77. I bought new a regulator, and a reman alt from Autozone. Tested the charging system after installing these parts and was over charging! Long story short, after 2 days of trouble shooting and replacing the regulator again, I went to Napa and bought another regulator. It cost more than the 2 together I bought from Autozone but it worked! So sometimes even "new" parts are bad. But yes, definitely the voltage regulator.

[bhermes]

Thanks to all. This forum is awesome. I on the other hand am not so thanks for all the patience. I will replace the voltage regulator again and let everyone know if that fixes the problem. I am still concnerned that the ignition module is bad. Not sure if anyone has expertise here but would a bad ignition module typically cause the car to be difficult to start. The car has always started fine.

From a previous post it was said that the increased voltage from the alternator and subsequently the battery may cause the ignition module to do funny things.

Again thanks for the help.

[bhermes]

I will looking at replacing the voltage regulator and possibly the alternator. Someone mentioned a self regulating alternator and I am checking to see if one exists for my car.

With this said, is there something else causing these parts to fail or not act properly. I have replaced the alternator twice and the voltage regulator once and the baterry went bad after less than one year. Maybe just a bad voltage regulator but curious if there is another part in the equation I am missing.

Thanks for all the help.

[5thhorsemann]

If youre alt is putting out 17 volts, it's okay, change out the regulator.

Look at the MSA link and search the catalog for "alternator upgrade" there is a plug that replaces the regulator that contains a diode to accomodate turning the car off and draining the battery when sitting. Then all you need is a internally regulated alt. I'm just not sure if you would use the same plug and alt as a 240.

[bhermes]

OK. Just want to make sure I make the right corrections. Does the car have two voltage regulators, one internal to the alternator and one external? Are we talking about the external regulator?

Where is the MSA link?

I actually had my mechanic replace the voltage regulator before just because he was looking into a few other things on the car so I am taking back to him to have a new one put on. I will get this one from NAPA. I think the other may have come from Auto Zone or OReilleys. Taking car early next week and just want to make sure we have the right parts on the way.

Thanks for all the help and patience.

I bought the car to learn and you guys are helping me along my way. Once I paint this car over the summer I plan to buy a couple more for my sons to work on.

[Zed Head]

1976 came with an external regulator. It would be mounted underneath the metal "shelf" by the battery with all of the other electrical components. You wouldn't have an internally regulated alternator unless someone had modified your car to have one.

Checking the alternator and voltage regulator for proper operation is pretty easy. Your mechanic should be able to do it before he changes the regulator. A good mechanic would have checked his work the first time.

[Willoughby Z]

No, you only need one regulator for voltage. OEM set-up was an alternator with a fender-mounted voltage regulator (external), meaning, not part of the alternator. You can replace an alternator with an internal regulator (meaning the regulation is part of the circuitry) but you must bypass the stock/OEM fender-mounted voltage regulator.

MSA link:http://www.thezstore.com/page/TZS/CTGY/SEIC03A

Yeah, what Zed said...

I type slow

Edited February 23, 2012 by Willoughby Z
late

[Willoughby Z]

This is the upgrade connector:

http://www.thezstore.com/page/TZS/CTGY/SRC19

This info for doing the upgrade from external (w/ VR) to alt./ internal regulation.

http://www.zhome.com/ZCMnL/tech/280Alt.html