I was wondering if I could get some help on changing my heater switch.
The heat only used to work on high for the longest time, until recently nothing comes out. I bought a new blower motor, & ive changed the resistor that I got from a junkyard..the fuse is good.
So by process of elimination Im down to the switch.
Any help would be great. Thanks

 

The blower-speed switch controls the blower speeds via the ground to the blower motor. HIGH speed is a direct ground to the motor. The other speeds come from the resistor pak....three speeds with the LOW being the highest resistance circuit. The resistor pak from the junk yard may be bad....the pak also contains a termal-limiter which could be dead too. The blower switch can be removed from the function-control panel by pulling the electrical connector, removing the screw that mounts it to the panel and taking off the **** on the switch. It could very well be the switch, but I'd suspect the pak first. Also Fords had a wiring problem in the harnass back then....I had the problem in my '81. Need anymore help....just email and I'll try.

 

If it is the switch you will probably find the plastic harness connector has melted. They are available after market under brand names PICO or STANDARD.

 

Thanks for the replys....Is there a test I can do to see if it is the Resistor??

 

You can do a continuity test on the resistor. You should have continuity between all four of the terminals with varying resistance. The resistance should be no more then 5 ohms at max.