78 GMC sierra classic-Radio and Heater fan stay on after key is off

[chev2low63]

First post... My 78 GMC Radio and heater fan stay on after the key is off. If I disconnect the battery and then reconnect, it doesnt come back on. Ignition switch??? any help would be very appreciated!! thanks

[Irish_Alley]

First time I heard of this but like you said the only thing that I think it could be is the switch

[chev2low63]

thanks irish, im just gonna keep fishin around for a while. maybe its something stupid easy!

[Blazin]

I had a 66 Chevy on a 70's chassis with a mix breed of 66 and 70's wiring. Had a kill switch, and a momentary push button switch to start it. The truck would shut off fine unless the wipers were on, then it would stay running until you shut them off!

[chev2low63]

one more thing to add:The light on the radio always comes on when the truck is on,  no matter if the radio is on or off. When I reconnect the battery and start the truck, if I dont turn the radio or the heater on it will go off when i turn the truck off. just brainstorming. thanks!

[zieg85]

Sounds like a back feed from something being added.  What after-market stuff has been added? 

[chev2low63]

There is a CD player is and there is an amp, those are the only aftermarket electronics. All I did was replace another deck and amp that was already in the truck.

[zieg85]

Unhook the radio, does the heater fan stay on after the key is off?

[chev2low63]

the heater fan does stay on when the radio is unhooked. I also disconnected the heater fan and kept the radio powered and it still stays on. Another thing thats strange is when the truck is off the radio and heater are going if I hit the power window switch and hold it the radio will go off but when I let up on the switch it comes back on. Think im just gonna replace the ignition switch for starts. thanks everyone for helping!!

[chev2low63]

replaced ignition switch and its doing the same thing.

[Irish_Alley]

How does your junction box look under the hood

[75blazer]

happened to me recently. problem fixed itself but i learned it can be a couple things. 1. the ignition switch at the bottom on the steering column is loose or broken. 2. the rod inside the steering column can be out of adjustment (not likely).