I've searched a little bit but most of the threads here are about cores or resistor packs.

My heater hasn't worked since I've owned the truck, dash lights up but none of the switches do anything.
I've never done any work on a heater before so I'm just wondering where to start. I checked fuses and the wiring seems to be healthy although I didn't dig real deep. I'm assuming that the blower is either busted or not recieving power but I'm not sure I even know where the blower is

85 std cab no AC 22r

 

well not that anyone is listening but I'll continue to self diagnose

I found the blower while tearing my entire dash apart. I found a relay and 2 fuses mounted behind the switch panel for the heater/fan controls.

The fuses looked fine but I'm thinking the relay might be shot here is why. There is a white wire that is hot that runs into the right side of the relay and then a red wire (same dia.) that runs down to the left side of the fuse labeled heater. everything works if I pull the relay and use a jumper wire from the right side to the left side. The only problem is that it stays on even if the truck is off so I'm hoping to just replace the relay and have a working heater tomorrow

 

wish i could help, im just the opposite. my a/c dont work, but my heater owns. im lazy to get it fixed, but hey, its winter.

good luck mate.

 

For the blower, see:
- http://www.4crawler.com/4x4/CheapTricks/Blower.shtml

If there is no heat, check the cable at the valve on the firewall.

 

So this is pretty crazy, if I pull the relay and use a jumper wire in it's place everything works as it should. blower blows hot air and at it's differant settings. So I switched that relay with the one used for the headlights. Heater wont work headlights do work.

So both relays will power head lights neither one will make the blower come on

My logic: Blower works, switch works, relay works, everything else works as long as I have a jumper wire in place of a working relay.
What am I missing?

 

Sorry I can't help, but I have something similar happening.
My fan won't turn on on low. Only on med, and high.
I think that it must be worn contacts, but I still haven't gotten back there to fix it.

 

Sounds like a burned out blower motor resistor:
- http://www.4crawler.com/4x4/CheapTri...BlowerResistor