1. Home
  2. Jeep and Willys (new and old)
  3. Climate control panel overheating

Climate control panel overheating

I've searched the group and can't find a thread for this particular problem. I have a 1991 Cherokee Lorado. Recently, the heater blower switch heated up and melted the plastic wire loom. The switch got so hot that the plastic parts inside the switch melted and fused. I also noticed that one of the connections on the plug that goes to the heater/ac control panel (NOT the blower switch) also melted (only one of the six connectors on that plug). The first thing I suspected was the heater resister. I know that usually, when the resistor starts to go the blower will only work at high speed. That never happened in this case. Until the switch melted, the blower, heater and a/c worked fine. I replaced the switch and the heater resistor but the panel and the blower switch still get too hot to touch. The blower seems to work fine on all speeds, the ac works (it never got super cold but it does cool things off) and so do the other controls. BTW all fuses seem to be fine. There seems to be resistance in the system somewhere but I can't figure out where. Can anyone tell me how to trouble shoot the system to check for a bad ground or something? How can I check the blower to see if it is causing a problem. I can put a VoltMeter on it but I don't know what readings I should be getting.

Any help or ideas would be great. Thanks, Jim

Reply to
Jim
Loading thread data ...

Well the same thing happened on my 93 Cherokee. I smelled something and then the fan quit. I took the dash apart and found the melted mess. I went to the junk yard and found two others melted before I found a good one. I cut the wires with the switch and installed it in mine. I gave the Jeep to my sister and 5 years later it is still fine. Maybe it is a switch and load issue.

Reply to
f_wenzel

Your initial switch failure was probably a combination of two or more things.

- A blower which is drawing high current, the bushings might be getting worn out or the blower wheel might be lightly rubbing. This creates a lot of extra current in the circuit.

- A switch which was getting old with dirty contacts or terminals

Together these probably caused the switch and connector / terminals to overheat.

You replaced the switch (did you replace the connector and terminals too?) which fixed part of the problem. Check out the blower and if it is rubbing lightly or a little slow it should probably be replaced as well.

Things like bad grounds or corroded terminals add resistance into the circuit and decrease the current. But they can be the cause of local overheating if there is high current in the circuit.

reboot

Reply to
reboot

I do not know about the rest of you? But replacing the blower sounds like it but be a pain in the neck to do. I know with my 99 wrangler TJ I have to take the whole dash up and out just to get to the blower motor. I think you may need to take dash out of yours to get to your blower motor. But I can be worng very easy. What I would do is replace the heater/AC control and if it happins again take a look at taking your rig to the shop But if you got the tools the skills and the time. Take a look at the heater control box under the dash and see if any of the motors are running hot or slow. Replace them if they are running hot or slow. I hope this is of any help. Jamie

Reply to
Jamie Mello

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.