1981 sx4 Heater/ac blower not working

[olymunch]

I was told that i have a burned control head and open circuit to blower motor and my cables are binding.
If I change the heater/ac control unit will it fix the problem?
I have to drive across country and its cold so I NEED my heater to work.
When driving on the freeway i get heat. The heater core is new.
Please help
Thanks

[BenM]

You'll probably need the resistor too. The two common failures are the resistors and the electric switch on the head unit, especially the "High" position on the switch.

See this wiring diagram

You could put a jumper through a 30A fuse and a switch from the battery to the positive terminal on the motor. I did that for a few weeks on a car before I got a new switch. You only get high, but it beats freezing. If you don't get the time to inspect all the wiring, it's the safest bet.

[olymunch]

WoW! Thanks! That's a huge help. I'm prob going to buy a new switch/control unit but I didn't even think about that. If i use a lower amp fuse will it be like putting it on med? What about the cables binding? Can I just remove them and squirt it with some penetraiting oil till they move and put them back in? Is removing the cables a difficult thing to do?
Thanks again
P.S. Where is the resistor and how would I know if it was bad?

[mudkicker715]

Lower amp fuse has no effect on speed.

[BenM]

Getting the cables out can probably be done by removing the glove box interior and the head out. You may need to drop the package tray too, but you shouldn't have to remove the dash. Penetrating oil may free them, but you'd be good to try to put maybe white lithium, or graphite or Teflon lube down the line. Graphite and Teflon are a dry lube with a thin carrying oil that can evaporate after a while.

They're usually just nylon-lined metal cables and don't have any lube in them.

The smaller fuse will just blow. The motor draws enough current that it would take a heavy and hot resistor to slow it. The stock ones are like that.

You ought to just be able to find the electric switch for it if you look. It may need a new connector too, it could be melted, but you won't know until you look.

[olymunch]

Thanks