key won't shut engine down, lights for in dash stay on, but everything else goes off

[SPR1NK]

When I turn the key off it shuts off the radio, but the engine stays running and the rear abs light comes on, once I get engine shut down by unplugging wire on IP the voltage light also comes on and no amount of tinkering with the key will get them to shut off

I unplugged the ignition switch to see if that would shut everything down but it didn't change anything, what am I missing, what could cause this issue?

 

[madpogue]

What year truck? Automatic or manual transmission?

Sounds like you have a crossed wire somwhere, energizing the FSS wire from another circuit. I would start by pulling both battery negatives momentarily, then reconnecting them. Then see if there's still voltage at the FSS wire. If so, start pulling fuses, one by one, until you see no voltage on the FSS wire. That might track down how it's being energized.

 

[OLDBULL8]

When I turn the key off it shuts off the radio, but the engine starts running and the rear abs light comes on]

Be more clear about this.
Are you saying the engine starts up when turning the key OFF, or does it just keep running after you have started it?

 

[SPR1NK]

Whoops, sorry, meant to say it stays running when I turn the key off

 

[SPR1NK]

Ok, so I pulled every fuse in the box and none of them took power away from the the voltage light or abs light or the FSS, when I pulled the battery terminals off and then put them back on they sparked big like there is alot of power draw somewhere, seems like it's gotta a be a big short, but I don't know what could short to cause this

 

[madpogue]

What year truck? Automatic or manual transmission?

 

[SPR1NK]

88 with the zf5 manual, like it says in my sig

 

[Knuckledragger]

Is this a new condition, or is it a new truck to you? Done any modifications (add equipment, lights, radio, TV, microwave, washer/dryer, etc)? Any long wires under the hood that look like someone else (not you, not the factory) put them there? All lights work? Do you have a tachometer (and does it work)? Does the RTS light work?

As simple as these trucks are, there are plenty of places to go to ground or cross wires, especially in added wiring.

 

[SPR1NK]

I've had the truck for three years and never had any problems with it, I recently installed the turbo and made my glow plugs pushbutton, put a new stereo in it as soon as I bought it and never have had any electrical issues before this

Yesterday it did refuse to shut off until I brought the key all the way back to accessory tho, and then it worked fine after that until this morning

 

[madpogue]

And you still get 12V at the FSS even with the ignition switch disconnected? Your last statement kinda points at the ignition switch, but if disconnecting it doesn't help, then it's head-scratchin' time......

 

[SPR1NK]

Yeah, ignition switch I thought would've been the obvious culprit and I figured disconnecting it should've shut everything off, so I'm at a loss as to what the problem is now

 

[TronDD]

Had this in my 91. It was that the glow plug power wires (which have power all the time) had melted the engine harness connector internally allowing the pins to touch each other. Not sure how different 88's are, but check the plug (passenger fender in a 91). Actually unplug it and look at the inside. Mine was relatively unchanged on the outside.

Folks rerun the glow plug wires outside the connector for this reason.

Tim.

 

[madpogue]

^^^^^^ Reminds me of another possibility. Glow plug relay. If it epic fails internally, the always-hot contact terminal can bridge to the switched coil terminal, which can back-feed power to what is supposed to be a switched circuit. MIGHT be worth disconnecting the GPR terminals, see if that makes the power to the FSS wire go away with key off.

 

[laserjock]

I suspect it's in the Gp system or check the alternator. They can short internally. There's another almost identical situation going on with another member right now. His truck I think is going through a no start, gp controller acting crazy etc.

 

[SPR1NK]

The gp controller is completely bypassed, how plus are just using the solenoid and a button now, the controller brain box thing is only still in there to serve as a place to mount the solenoid, but I will double check it to see if something is so hooked to it and maybe it is the culprit