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292 Y Block Alternator swap

Posted: May 21, 2015, 2:25 pm
by Holly100
My question is just about the wiring for a three wire GM alternator. Does the positive bypass the voltage regulator? Is there anything special to wiring the warning light...anything to bypass there? How do you wire the 3rd wire?

Re: 292 Y Block Alternator swap

Posted: May 21, 2015, 3:57 pm
by Toyz

Re: 292 Y Block Alternator swap

Posted: May 21, 2015, 4:40 pm
by unibody madness
Run the charge wire to the selenoid battery side.
Run the #2 spade wire to the same place.
Run the #1 spade wire to the idiot light, make sure the idiot light is hooked into accesory on the ignition switch on the opposite end.
The regulator is no longer needed

Re: 292 Y Block Alternator swap

Posted: May 21, 2015, 5:20 pm
by Toyz
The original regulator is no longer used; the Gm 3 wire (and 1 wire conversions) have a built-in regulator. You can remove the old regulator and wiring or just tape the old wires back into the harness. The wire on the "I" terminal of the original regulator can be lengthened and tied into the above noted charge lamp terminal to avoid disturbing the instrument panel.
As John stated; it is advantageous to run the other two wires, the heavy gauge, and the lighter gauge; to the battery side of the starter relay. This allows the regulator to sense voltage at the point at which power is distributed.
Paul

Re: 292 Y Block Alternator swap

Posted: May 22, 2015, 11:40 am
by Holly100
Thanks, I figured I was over thinking it. Is the horn relay tied to the regulator at all? Is a small 63amp alternator enough? I'm not running air or even a radio.

Re: 292 Y Block Alternator swap

Posted: May 22, 2015, 11:47 am
by Holly100
Toyz wrote: The wire on the "I" terminal of the original regulator can be lengthened and tied into the above noted charge lamp terminal to avoid disturbing the instrument panel.
I'm a little fuzzy on this. So keep the old regulator?

Re: 292 Y Block Alternator swap

Posted: May 22, 2015, 1:55 pm
by Toyz
No, just take the wire from the "I" terminal of the old regulator and lengthen it to tie into the new alternator terminal per the drawing. This saves you from running a new wire from a key activated source through the warning lamp then to the new alternator. You can then secure the old regulator wires back into the harness and remove the old regulator. 63 amp is more than the original and should be fine with few added accessories.
Paul

Re: 292 Y Block Alternator swap

Posted: May 22, 2015, 2:26 pm
by unibody madness
Yep.
if you unwrap the regulator feed, you can see the wires that feed the horn relay. I used the original wires in the regulator loom to wire the alternator. Cased it in. the plastic loom cover from harbor freight