Thread: Wiring question voltage regs.

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I have a newer alt. less than 2000 miles and it is dead.

It is internally regulated alt., but I think that there is an external regulator also.

What problems would this cause? It is a '68 chevy. (a hot rod in my eyes )

I am not sure of the wiring, can't find a diagram anywhere.

Thank you,
Zachariah

Is it a one wire alternator or does it have a two wire plug and the one battery wire ? And if it has the plug what year car is it off of ?

It is a three wire, one bat(the red) and has a place for a plug with two spades. I don't know where this particular one came from, it was there when I bought the car.

The alt is listed for the car at the auto parts store, they have both internal and external with the same three wire design.

Thanks

PS. I have found an external regulator on the car. looks like it is the original style. It is hanging from the headlight brace with a ground wire bolted to it.

There is also another loose wire at the yellow and blue wires but I can't tell what color it is. (makes two unused loose wires at the alt.

alt and the three wires connected and two not connected. The big black tube represents the wires where they are wrapped.

Your alternator is the external regulator type . Starting in 1973 GM went to the internal regulator alternators . The best thing to do is pick up a power master one wire alternator with the one wire hook up . Then all you need to do is hook up the red battery wire and unplug the the body mounted regulator . And this should work and charge much better then the factory set up did . Or if you have a good 1973 to 1980 Chevy alternator with the plug I can tell you how to make it work on your 68 chevy wiring . I think its better to go with the one wire alternator . I have seen them at some local auto stores . A 70amp is enough for your car .

This is the only one I could find on my computer.......

I have read that one wire alts are problematic and should be avoided.

if I get a "oem" alt and new reg. how does it get plug back in? (see attached photo)

also if i go with a 73+ can you explain how that would work. I had a 75 and never had any probs.

Thanks

Originally Posted by shawnlee28

This is the only one I could find on my computer.......

Thanks Shawn.

Thanks Denny

I think we posted at the same time
Thanks,
Z

i have a GM alt on my mustang .. i use the tie the two wires coming out of the pig together and use a diode to prevent back voltage then join the big red wire and head for the battery technique .. .. if you cant get anything else to work look up onewire alternators on the web and the system i use should pop up ... surely your stock wireing is`nt butchered up so as not to allow you to remain near stock though

OK I have decided to go to the internal reg. Alt. A GM 3 wire.

I would like to keep a working GEN Light if possible.

How should I go about doing this. What are the connections on the '73+ for?

Thanks
Zachariah

I have read the following site:
http://www.rowand.net/Shop/Tech/Exte...Alternator.htm

I am a visual learner and think that I have found the solution. What do you think

(this is a modified drawing that Denny provided. Do this look correct. it seams to easy )

Here is a close up if you can see it of the proposed changes I want to make.

If it is really this simple, everyone should do it. It would make sense why GM did it.

Thanks for all of the help. It will really clean up under the hood.