fan/heater stays on after shutting truck off?
 

So when i shut my truck off the heater will occasional keep blowing. it also has a string of LED type lights inside the dash by the speedometer, those also stay on sometimes. It's happened before and we thought we had it fixed. We had a whole new fuse box put in and some kind of module. Does anyone have any ideas of what could be the problem? im thinking maybe some kind of wiring? i appreciate any replies

This is becoming more common.. The blower motor relay is what controls the motor..
When it stays on do you have all the speeds? Pull the blower relay see if it stops.
Does it go off when you put the blower switch to off..?

yes all the speeds work just fine, and i've tried putting it to off but you can still hear it running. But i'm not real mechanically/electronically inclined when it comes to stuff like this, care to tell me where the relay is?

Under the hood in the fuse relay box. Do you have a standard dash heater control etc off is up..?

Is there any sign of water in the cab, driver's side? If the windshield is leaking, it will run down the a-pillar, and drip right on the fuse block and GEM. The blower staying on is common - happened to me. You have to take off the two big connectors on the back of the fuse block and blow them out with compressed air.

Funny thing on the 99 the gem doesn't have anything to do with the blower stuff..Now the fuse box does if it shorts...At least on my 99 CD.

Well I found the fuse to it so I pulled that for tonight so it didn't die on me again (didn't pull it last night, went to go to work and what do you know batteries dead) but I'm gonna get a new relay tomorrow and I noticed a few blown fuses so I ned to replace them while I'm at it.

I have the same problem, I have a leak in the windshield like WestCoastTodd mentioned. When it started there was no indication of the leak because it would run along the headliner then down the pillar and shorted something out. you may want to check that out. Also in my case I just turn the heater control to off when I trurn the truck off and the blower will turn off. Its easier than pulling the fuse whenever you want the blower off.

I have this same problem. Did the blowing off of the fuse connectors fix the problem? I also have a problem with the daytime headlights coming on arbitrarily

Ditto on the windshield leak, that's probably why you had to have the fuse panel and GEM replaced in the first place, take it in and have your windshield resealed, then dry out your fuse panel and GEM.