kw62583

I have a 66 Cutlass with a mid/late 70's 350 in it, the swap was done by a previous owner and included the HEI distributor and internally regulated 3 wire alternator. I do not know how they wired in the alternator other than the regulator on the firewall is bypassed. The HEI distributor still had the resistance wire running to it when I got it so I replaced that with a switched and fused 12v wire coming from the distribution block on the drivers side fender. Until yesterday my gen light on the dash has been working normally, key on engine not running it was on bright and when I fired it up it went out. Well yesterday when I got to work I turned the key off before killing the power to the distributor so she kept running for a few seconds until I hit the switch (don't know if it could have caused something to fry). When I fired it up to go home the gen light didn't come on when I turned on the key and when I fired up the engine the gen light was dim. Also the aftermarket volt meter was reading real low, something like 8v with key on and only 10v running. When I got home I grabbed my volt meter and checked the battery and I was getting 14.8ish running and 12.3ish when off so from a charging stand point it seems to be working properly. I also checked at the fuse block and I'm getting the same there. Headlights and dash lights don't seem to be dim. I don't know much of anything about automotive electrical other than the basics. I am guessing the volt meter is tied into the gen light since they seem to be the only two things acting weird. What could be causing this, where should I start looking, what should I do to trouble shoot this?

oldcutlass

This is how most v/r's are jumpered. The brown wire goes to the gen light with 12v on both sides of the light it goes out. If you have less voltage on the brown wire than the pink wire that supplies the light on the dash it will glow. You may have damaged your internal regulator.

White_Knuckles

Yeah, I had issues with a dim GEN lamp intermittently popping on with the three wire, reg. setup. I tried a solid state regulator which made it worse. The fix for me was to disable the regulator device simply removing the connector. I switched over to a one wire alternator and secured the other factory wires at the Alt. The Summit replacement has more total amp output and works dandy fine. The GEN lamp never comes on. Not a concern for me. The self regulating Alt. seemed like it would stop the madness. It did indeed.

kw62583

Thanks, I'll check the voltage going to the light.

stellar

Sounds like a blown fuse.

kw62583

Thanks guys for your help, I finally got some time to diginto it and got it working. I found outmy alternator was good but I had several problems contributing to the gen lightissue. After I determined the alternatorwas working I started checking wires and everything looked good until I gotunder the dash. I found multiple crackedwires along with several of the factory splices partially exposed. I patched the under dash harness up andreinstalled it. While reinstalling it I foundall the instrument gauge circuit board pins were loose. I found a great wright up on here on how tofix it, I got some 1x72 screws and screwed them into the back of the pinspulling them tight against the circuit board. After all that was finished up and put back together the gen light wouldnot come on at all so I checked the fuse and it was blown. I replaced the fuse and everything worked untilI went to back out of my driveway. Assoon as I put it into reverse the gen light came on bright and then died, fuseblown. So now I know I have a shortsomewhere in my reverse circuit. For nowI have the reverse circuit disconnected from the switch.