Well this has been a problem since I bought the truck in '93 but now it has stopped working completely... I took the fan out and connected it directly to the battery and it works fine so it must be the control panel... Anyone know where I can get the heater components? I might as well change out the fan while I am at it... It does make a racket at times.. Lots of squeaking and such especially when I first turn it on... Any help or suggestions will be greatly appreciated....as usual..

Happy New Year

Guns

MAGA

 

Think we may need a little more information.
First what is it NOT doing that it should?
Does the truck have factory AC, dealer installed AC or no AC?
What is it on the control you are looking for to replace?
IIRC there was a post that showed what each port on the control switch did so you could trace it out.
Dave ----

 

Before getting too crazy, try wiggling the key. On my truck, occasionally the ignition switch doesn't completely spring back to RUN after releasing the key from START. The engine keeps running, but the heater fan is dead until I wiggle the key.

 

Check this first. A very common problem on these trucks, and is especially bad in the winter when the grease gets cold in the steering column.

 

Good point about the temperature. Now that I think about it, the problem has only happened on very cold mornings.

 

Yea that was the first thing I tried.... Then fuses.. Then took out the fan and tested it.. I bought a voltage tester today and I will do what I should have done before pulling out the fan which is check the plug to see if it has a current to it... If is doesn't I'm thinking it is the switch itself... Anyone know how difficult it is to change out the control if it comes down to it?

Thanks

 

Oh.. and no AC....

 

Having been here for almost 10 years, I can say from experience the problem is not likely to be the switch... I agree with jiggling the ignition switch first and do some diagnosis from there. The switch controls the current to the fan-motor resistor (located inside the plenum) and operates on the negative side of the circuit IIRC... look at the EVTMs on Gay's site, there should be some diagnostic ppocedures listed in those things,

 

Take your voltage tester and test both sides of the 30 amp fuse(with the key on). If you have it there, then you can check over at the switch. Here's a diagram for a 86, yours should be close to the same.

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=27256

P.S. May be easier to check for voltage at the motor. If you look at the diagram, they just send 12v to the motor when the dash switch tells it to run, and it's the negative of the motor that has the speed resistors in it.