1991 GMC Vanudra 3500 Wiring Schematics?

[Vanduradiesel]

Hey there guys, I'm new to this whole school bus conversion thing and know virtually nothing about it. I've got a pretty serious power drain on it somewhere, and my current objective is to just get it roadworthy. My main concern is just running what's absolutely necessary. Does anyone have any clue where i might be able to track down Schematics? Like i said, i'm not worried about the secondary fuse panel for the school bus functions. Thanks!

[Veloc]

Don't know on the wiring diagram, but a clamp-on ammeter is the way to go here. Clamp it over the positive main battery cable and it should read the drain you see. Then you start pulling fuses, one at a time (and put them back if it's not the one,) and see where the drain stops. Once you find the correct fuse, you know what circuit to work on.

Your local GMC dealer service desk may be able to get you a printout of the wiring. Try 2-3 different dealers, not all of them are car guys. The ones for whom it's just a job won't be interested in trying to help. If that doesn't work, you can try ordering a manual from these guys. I've used them a few times in the past on passenger vehicles, never tried for a bus though.

[Vanduradiesel]

Originally Posted by Veloc

Don't know on the wiring diagram, but a clamp-on ammeter is the way to go here. Clamp it over the positive main battery cable and it should read the drain you see. Then you start pulling fuses, one at a time (and put them back if it's not the one,) and see where the drain stops. Once you find the correct fuse, you know what circuit to work on.

Your local GMC dealer service desk may be able to get you a printout of the wiring. Try 2-3 different dealers, not all of them are car guys. The ones for whom it's just a job won't be interested in trying to help. If that doesn't work, you can try ordering a manual from these guys. I've used them a few times in the past on passenger vehicles, never tried for a bus though.

Okay thanks, I'll get one and try that. I hate electrical problems and just want to be able to run this thing on the road.

[Jolly Roger bus 223]

your local auto parts store can get you a haynes or chiltons manual for about 20$