Well, the coldest day in a month, the dang heater motor isn't working! I checked the fuse, it is fine but I might swap it out anyway even though when I put it back in it sparked a little on the contacts like it is good. I checked the 2 wire plug under the hood to the motor, it is solid. Have not pulled out the VOM yet but are these notorious for the switch going bad?

 

if you have power at the fuse it is possible the switch is bad but if you do not have power at the fuse it could be a fusible link. does your truck have power locks or windows? i think they share a fusible link with the blower motor.

 

My truck is a Cromagnon, no power anything. There is a fuse in the block that says heater and AC I think, I know it says heater. It LOOKS good.

 

I am starting to think it might be I pulled the plug away from the back of the switch because I was messing around with my stereo whic has a TON of wires, and RCAs plugged into it and it sits right below the heater switch controls. I was messin with it the other day right before I realized the heater had quit trying to find the source of a scratchiness on AM radio.

 

well if you have power at the heater fuse then i would check the switch. checking the fuse for power will probably be a bit easier than taking apart the dash and finding out it may or may not be the switch

 

I can easily slide the radio out, get access to the plug on the back of the switch and see if I pulled it loose so will do it tomorrow or Saturday when I get a chance and it warms up a bit. Gladly I have a DD that gets better mileage!

 

on a cold day if i was in a rush something like that would just get hot wired in my truck. if i wasn't in a rush i would fix it properly. with how many electrical problems i have helped people trouble shoot i have learned a great bit about the wiring on these trucks.

 

yeah, that wasn't it. The switch being unplugged in that is. Is there a relay?

 

no relay. so it wasn't the switch? if the switch is plugged in i would guess you might have a bad fusible link.

 

My heater was working fine one winter and then the next winter the fan speed switch wasn't working. I had unplugged the fan and used jumpers to the battery and it worked. I took out the switch for the fan speed and it looked good. I followed the wires from the fan speed control back to the heater controls by removing the stereo and there it was. The plug had slipped back some when messing with the stereo over the summer. That plug is pretty loose on mine so it slipped off easily.

So what exactly is not working on yours? Mine had heat while driving but no fan control. Some common problems are trash in the heater box blocking air flow and corroded diverter valve for the coolant going to the heater box.

Good luck with it. It's too freakin' cold to go without a heater right now.