Electrical Problem

robertgm62 · October 27, 2011, 12:55:53 PM

First off I would like to say hello to everyone.

I have a 1962 GM I went to go fire up the bus two day's ago it turned over just fine as being a cold blooded Detroit I turned the switch off ran back to shoot some either in it and went to hit the button and Nothing I changed the push button switch seeing my bus still has a lot of the Original parts in it and still nothing I am getting juice up front for everything but I am not getting anything for the back end I have tested the rear electrical panel nothing there or on the alternator I don't know if there is a relay switch up front that help controls the back I didn't see anything really in the book all wiring looks good and not broken I am also charging the battery's just to make sure there fully up the generator light on the panel is lit up but goes on and off I am new at this and trying to learn the ropes any information would be Gratefully Appreciated.

I also noticed in the Repair Manual something about rear start I don't have this Option on my coach if someone has a Diagram to go by that I may put on in thank you.

gus · October 27, 2011, 01:56:23 PM

You need to post the bus model and engine.

GMCs are infamous for starter relay failure which is probably located in the rear electrical compartment.

Fred Mc · October 27, 2011, 02:03:20 PM

If this is a 4106,In the rear electrical panel(behind the pasenger rear tire) there is the starter relay. Upper left hand corner. Take the cover off and press one of the contacts. It should energize the starter.

papatony · October 28, 2011, 04:30:09 AM

on the 4106 the panel in the rear engine has a switch to kill the front start if some one is working on the engine. if this doesn't help I have the electrical digrams tony

robertgm62 · October 28, 2011, 12:08:53 PM

it is a 4106 8v71 Yes Tony that would be great but there is no switch in the back panel that I could see.

gus · October 28, 2011, 12:15:23 PM

If the rear switch panel is like a 4104 it is high on the right side out of view, you have to stick your head into the engine space to see it.

It consists of three switches if none are missing (at least one usually is) and is not easy to see/find. It is easy to hit the engine stop switch by mistake, I did it at least two times. You learn quickly once you figure it out after the first time!!

robertgm62 · November 03, 2011, 10:56:02 AM

thanks for the heads up gus i looked up and seen were it used to be mounted I ran a new switch and found that Original Battery cable was broke in two ran a temp, tested new switch started up with one rotation I luv my bus, thanks for all the input.

gus · November 04, 2011, 07:35:10 PM

Robert,

Glad you found the problem. Broken and/or corroded wiring is an everyday problem with these oldies so it usually pays to poke around and trace the circuits.

My start switch panel is in pretty bad shape and I've wired around all but a couple of circuits, plan to completely eliminate them soon because they are exposed to engine compartment dirt and grease. They aren't inside a nice comp like on the 4104 and, I think, the 4106.