Blower only works on high, fuse is good. I read the resistor is supposed to be under the glove box, but I can't find it. 85 with a/c.
Cruise control doesnt work, I got as far as checking the fuses, brake lights and vacuum hoses, any resources on troubleshooting? 5.0 FI.

 

The blower resistor is under the hood. It looks like a wiring plug plugged into the ductwork. They mount the resistor there so the airflow from the blower keeps the resistors cool, they get red hot and like to set leaves on fire if they get into the duct.

If your resistors are good, I have found on some of the later models(I don't know if the earlier models had this) there is a thermal fuse in the resistor network. It looks like a small silver barrel. It's the same type they put in coffee makers, but I don't know the rating that Ford used. If you have one, check it for continuity. If it's open, that's probably your problem. I have wired around them and put them back in, but you can do this at your own risk.

The cruise control can have several problems. Do you have vacuum to the system under the hood? Is your brake switch going to the system ok? There is also a vacuum switch on the brake pedal. And another problem area is behind the steering wheel. There is a set of contacts back there for the switches. Does your horn work? It uses some of the same contacts, and I believe also the cruise buttons get there supply voltage from the horn circuit(fuse).

 

Thanks, that gave me a few things to look at. Horn works. Was working on my daughters 91 crown vic and noticed it has the same cruise control.

 

Dave - The 81's have the thermal protection in the resistor pack. I had the pack out of Dad's the other day and noted it, and then saw it in the wiring diagram.

 

The front side (where the wires connect) looks like this:





See if these threads help you:

https://www.ford-trucks.com/forums/9...s-on-high.html
https://www.ford-trucks.com/forums/1...stor-fire.html
https://www.ford-trucks.com/forums/8...g-trouble.html

 

Read all of those, good info in there. Think I'll prolly find more leaves in the cowl, and I'll pull the kick panels as well. If it lookslike the thermal fuse, I might try replacing it, I know a tv/appliance repair guy, I bet he has one.

 

Or Radio Shack.

 

Cellphone Shack went out of business a few months ago.

 

Ahhh yes, you are way out west. Prolly near the town that is a contradiction of terms - Liberal and Kansas.

 

If you figure out what the temp rating of the original is, write back in and let us know. It would be sort of like putting in the wrong fuse in the fuse box if you just "put one in" without knowing the rating. It could be too low and give you trouble opening up prematurely, or be too high and be the same as me putting a jumper in and not do any good.

 

Got a used one today, works! See the pics in tge "what did you do to your truck today".