Heater control

[kartvines]

On my 83 Pace Arrow, the A/C and Heater control , the high fan switch does not work, it will only blow when it is one step lower. Is there any information anyone could provide me with on what the cause or problem is and if it can be corrected? On another post it suggested it could be a fuse, but being I tested it good that was not the problem.

[goreds2]

It could be a blower resistor issue and may need replaced. My Nissan truck had that problem when certain speeds would not work.

[ccook129]

You didn't say if its Ford or GM,but I would think it might be a vacuum problem,check lines for a leak.

[nbounder]

If it's a GM, some of these use a relay to turn on the blower high speed. At lower speeds, the 12V goes thru a blower resistor as noted above. I'd turn the' em on to high, then tap the resistor & relay and see if you can isolate the problem. These components are generally found in the engine compartment over on the passenger side, against the firewall.

[justimagination]

Most GM's have a HIGH BLOW RELAY located normally on the evaporator case, best I remember is 3 wire, and the high blow wire is between puprle & pink in color, about a 12 gauge wire. Good luck, hope this info helps, been a while since I fixed one. Travel safe down the yellow brick road.
David G.