Emergency Door Lock Switch Keeps Me From Starting?

[FriendshipHouseBus]

Hello,

Our 1994 Chevrolet G30 Carpenter (Buster) has developed on odd issue. It seems to act as though the kill switch wired to the emergency door lock is keeping him from restarting.

The issue is intermittent. I will fiddle with the switch and it seems after 20 mins, all is right and Buster roars back to life as if there never was a problem. During the fiddling I never find any evidence as to what is causing the issue.

The switch is wired to allow starting when the dead bolt presses the switch.

Do wiring diagrams exist where I can trace the wire and find relays, grounds, or what have you that may me contributing to this fault?

Any input is greatly appreciated.

[BlackJohn]

Describe your fiddling. Have you opened up the box to see what is what?



John

[CaptSquid]

"when the deadbolt presses the switch"

This would indicate an open in the circuit. Try taking the switch off of the door jamb. Ordinarily, when the E-Door is open, the circuit is complete via the chassis ground. If you take the switch away from the chassis, the circuit is open.

[FriendshipHouseBus]

My fiddling starts with pushing the switch in an out several times. Then taking the switch off the door jamb and wiggling the wires. Then trying to start with the switch off the bus. Then reinstalling everything and trying again. When this fiddling produces no results and I turn to defeated head scratching for several minutes, I give it one more go and Buster is back.

The switch on the door is a normally open momentary push button. With the lock open, it pushes the switch and closes the circuit. It has a wire going to the switch and then the switch is grounded to the body.

I would like to see how the switch is wired to the starter. The live wire runs inside the body. But it is red and there are several red wires under the dash and under the hood. Is there a way to get diagrams from Carpenter? I cannot imagine Chevrolet having the wiring diagram since this wiring was done at Carpenter.

[brokedown]

I removed all my interlocks because they didn't perform a useful function any more. The switches are as old as the rest of the bus and likely unreliable, and you end up with mystery no-start problems.

[o1marc]

Just disconnecting the wires on mine disabled them.

[FriendshipHouseBus]

I would like to keep the switch, as we still use the bus to transport students and I want to keep the kids and our drivers safe.

I am just unsure if it is indeed the switch. The main reason I think it is the switch is because the bus acts the same way with the door locked. But I have no conclusive evidence. The problem just seems to fix itself after 20 mins or so.

I put in a secret bypass starter switch today. Just as something to have as a fail safe should the issue pop up again.

When I get a chance I can post a photo of what the switch looks like and how it is wired.

Would I be able to get a wiring diagram anywhere online? Or even Carpenter themselves?