Fan Won't Blow on High

[Rednek1280]

I had my Jeep parked for a few weeks. When I started driving it again, the fan wouldn't blow on high. After driving it for a couple of weeks, it started blowing on high again. That only lasted a week and now its been a couple of months and still won't blow on high. I'm just hoping this isn't something to do with big electrical issues. Electrical is my weak point. Any help would be greatly appreciated.

 

[luis]

Is it overheating?

 

[clemtiger8]

My tj did something similar. Mine wouldn't blow on low. I changed the switch and it fixed mine.

 

[Rednek1280]

No, its not overheating. I'm talking about the fan inside for AC and heat. Low is the only speed that it'll blow on no matter where I put the dial.

 

[JPNinPA]

Pull out the console and look at the wiring at the back of the switch and the connectors. You might even unseat and reset them. But mainly look for any signs of melting.

Jeeps have no cabin filter for the air entering the blower. This leads to moisture and dirt corroding and slowing the fan. It also causes higher currents. These high currents melt wires and oxidize contact causing more heat and melting.....

 

[Utah_jeepster]

There is two possible things wrong, one is a cheap fix and the other is going to cost you a 80-100$.

First there is a resistor for your fan. Its located next to the fan motor in the passenger foot well area. They are relatively cheap and easy to replace. Which makes it your first choice to see if it is the problem.
The next one is the "heater controller", I know your going to say its your fan, but the heater controller is a fancy name for the whole heat/AC and fan controller unit. Jeep in its infanet wisdom doesn't want to sell just the fan switch, which is a known problem, so you have to buy the whole controller unit. Got mine several years ago from Auto-zone for 80$ or so. (lost high and second low). Its easy to replace, but its hard to get over the cost for one fan switch.

 

[Rednek1280]

Well it wasn't the resistor. On to plan B.

 

[JPNinPA]

It shouldn't be the resistor ( though you found that out already) you have the high setting with an issue and the lower ones work. The High setting is a short, no resistor, and is the least likely to overheat and fail. The lower settings typically go first.
Look at the wires on the back of the switches/controls. They are likely melted there or look at the resistor connector. The connector might be melted. This is definitely a switch,wire, connector issue.

 

[Rednek1280]

Its not just the high. The lowest setting is all that it will blow, no higher.

 

[Rednek1280]

Its not the switch. The wires all look good. No sign of melting on either the plug into the switch or resistor. Any other suggestions?