blower fan works only on high

bheidema · Member Joined: 28 Oct 2006

1991 cherokee heater fan works only on high speed. i changed the fan switch and the plug going to it which looked "melted". after checking junk yard i found many electrical plugs in same condition...semi melted.. going to the fan speed control.a problem with this year??..it does have a/c..any where i can get a wiring diagram? any help appreciated

87Eugenejeep · Member Joined: 05 Nov 2006 Location: Eugene, Oregon

I think this is common in XJ's I have a 87 with the same problem, Keep looking in the junkyards.

jarnkm · Member Joined: 05 Mar 2005 Location: Tuskegee, Alabama

This is a common problem that has gone unaddressed in the majority of Jeep Manuals, except the expensive factory Shop Manuals. Personally, we have a '91 and '93 Cherokee 4x4, along with a couple of often needed spares. A major consideration that a club needs to offer to its members/viewers is the access to good electrical information and diagram sources. As a mechanic and shop owner for over 40 years, I constantly complained to supposed repair manual suppliers that their electrical sections were severely lacking. No owner wants to give an arm and a leg to get a simple (working/usable) wiring diagram for his/her heating/AC system so that he/she can take a simple VOM and troubleshoot the circuitry. 99% of the heater motor problems lie in the failure of the diode in the resistor pack, located in the fan housing. The simple cure would be to just cut out and solder in a replacement diode. Next, a $25 and up replacement pack (if found locally). Having used my last "spare", I am looking for another myself. IF I can locate a decent diagram or a link for said supplier, I will post it. If I can locate an adequate diode that really does the job, I will also post it, along with the replacement procedure.

Good luck, before the big snow!