71 Cutlass

Was told if I went to the one wire alternator with internal regulator, that my "GEN" light would not come on if I ever needed to be warned of an alternator problem. Which wire goes to the "GEN" light, and is there another wire I can just splice it onto to keep the "GEN" light working? Still have external volt. reg. hooked up till 6pm tonite when I change it, so any posts before then that can comment on the use of those wires (if they are cogent to this discussion) would be great.

Thanks.

don71

Can't help you very much, but the idiot light used the brown wire that came from the external voltage regulater in 1971.

I know of no way to use the one wire alt. with the idiot light.

joe_padavano

Don't use a one wire alternator. The normal three wire 10SI uses the #1 wire from the plug to operate the GEN light. It also uses the GEN light to turn on the alternator at idle. One wire alternators typically do not turn on and start charging until RPMs exceed 1500. I am especially amused by the fact that the aftermarket has convinced everyone to use a one-wire alternator (which eliminates the GEN warning light) and now at least one aftermarket wiring vendor is selling a solid-state add-on device to restore the warning light function. Pay extra to remove it and pay again to put it back.

Or, you could save all that money and just wire up a stock 10SI that you can get repair parts for at any auto parts store.

71 Cutlass

I am using the 3 wire alternator as suggested(original hot wire and has a pigtail for GEN light and and second hot wire conection). Just installed it tonite...GEN light works....no problems. Only weird part was that when I pushed the "tab" on the inside of the alternator to set the polarity, I might have pushed too hard b/c it sounded like my screwdriver went through a buzz saw. Anyway, no ill effects after starting and test driving.

joe_padavano

You don't "set polarity" on an alternator. The hole and tab are only there for diagnostics. Normally you don't do anything with them.

71 Cutlass

I thought it was weird, but was told to do so by the salesman, and called an Olds guru in CA to confirm and he also said yes. Anyway...who knows with all this new fangled equipment.

BILL DEMMER

you need a new guru! lol
joe is correct, you don't polarize an alternator.
when you pushed the screwdriver in, it met up with the spinning rotor, you probably didn't do any damage to the alternator, just took off the coating on the rotor which will now rust.


bill

2oldsguy

When you insert a small screwdriver or any small metal rod into the D shaped hole you should hit a small tab on the regulator. When you touch the tab you then let the shaft of the screwdriver touch ground and you will bypass the regulator and full field the unit. It was a quick way of testing the alternator only, if it charged when grounded then you would replace the regulator.
As for the buzz saw, it was very common, you went past the tab and hit the rotor. No harm done.
Joe

71 Cutlass

Joe,
Thanks for your informed response. It was indeed a "D" shaped hole. Everything has been working great since the installation, just was a little more excitement than anticipated.