86 won't shut off until I let up the brake pedal

[JK5]

I was driving my 86 k30 to work today and it seems like some graemlins have taken over my rig. The first thing I noticed, the turn indicator lights were dim and working slowly, when I turn the headlights off, they worked fine. Next, when I tried to turn the rig off, it wouldn't shut off until I let up the brake pedal.

During break, I unplugged the light switch to see if that was causing issues.
That didn't change a thing. While I was under the dash, the box next to the brake pedal was making a buzzing noise, when I push on the brake. Not sure what that box is or does...(I'm a 73-80 guy). Also, when I turn the key, I get a quick buzz, while turning the rig off or on.

I'm starting to wonder if there is a short in the brake or ignition switch..

Anyone have any ideas what I should look at first???

Thanks in advance.

 

[JK5]

Also, when I take the truck out of Reverse (SM465) the truck will turn off, but when it's in reverse, it won't shut-off untill I let up the brake...

Kinda weird...

 

[mouse]

weird...start by checking out the ignition switch, I've seen some weird problems when they have failed.

 

[cegusman]

Could be a bad ground.

 

[atho]

Jerry, maybe if you can reach it, try unplugging the reverse light switch on the tranny and see if it still does that. Other than that, I dunno (I hate electrical crap).

PS, sorry I never called you back. I'll try to get around to that sometime

 

[blazinzuk]

I would check your grounds also.

 

[HarryH3]

I know EXACTLY what it is! I've had the same thing happen before. Remove the tail light housings and clean up the grounds to the body back there. Somehow, when those grounds don't have a connection, the backup light reverse feeds the coil through the brake light circuit.

I had the exact same symptoms on a K5 many years ago. I always backed into the driveway and if I left the trans in reverse when I shut off the engine, it would keep right on running. Shifting out of reverse OR letting off the brake pedal would let the engine shut off. I also had the dimly lit turn signal indicators, which was my clue that something was going on with the turn signal circuit. Once I cleaned up the grounds at the tail lights everything operated normally again.

 

[JK5]

You nailed it Harry!!!! Too bad I didn't see your post until today..

First I cleaned up the connections by the battery, that looked in poor shape.
Of course that did nothing for the problem. I unplugged the reverse switch like Atho suggested, the rig, now will turn off.

Then I noticed that when the rig was off and a turn signal was engaged, I'd get a tail light to light up. So..I jiggled the taillight harness and I found a lose ground.

This rig did some crazy stuff, the lights on the cab would flash...
The truck wouldn't turn off...just over a GROUND!!!!


Thanks Guys for the help!!!!