climate control fan only works on high

[JOBO]

Hey All,
I searched for this subject but could not find it in this forum. Sorry if it's been covered before.
The ac/heater fan in my 2005 Wrangler only works on the highest setting. I'm guessing it is a relay or a fuse. How do I go about troubleshooting it?...I'm a newbie.
Please and thank you.

 

[JPNinPA]

Its a resistor. Easy to access and change behind the glovebox

2005 JEEP WRANGLER 4.0L L6 Blower Motor Control Module / Resistor | RockAuto

Never look down on anyone unless you are helping them up - Jesse Jackson

 

[mark sr]

Hopefully that will fix it for you.
I used to have an XJ and the fan got where it would only work on high and then it got where it was slow to turn on. I lived with it for about a year and then replaced the fan motor to fix it.

 

[JOBO]

Thanks JPN for the video link. I'm going to try to do it myself, and I'll share the results here.

Its a resistor. Easy to access and change behind the glovebox

2005 JEEP WRANGLER 4.0L L6 Blower Motor Control Module / Resistor | RockAuto

Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JOBO]

Thanks for the input Mark Sr. I will keep the fan motor possibility in mind if the resistor pack replacement doesn't work.

Hopefully that will fix it for you.
I used to have an XJ and the fan got where it would only work on high and then it got where it was slow to turn on. I lived with it for about a year and then replaced the fan motor to fix it.

 

[JPNinPA]

Thanks JPN for the video link. I'm going to try to do it myself, and I'll share the results here.

No problem. Im sure you could do this.
Working in and under the dash is a pain sometimes but this one is straight forward.

Personally i think the resistors fail for 2 reasons. One is leaving the fan on lower settings when the engine is started. The onrush of current from the fan starting is too high fir the resistor for repeated occurrences. Second is electro-migration. If you look the resistor is made of different widths and lengths of serpentine copper traces. This by physics gives different resistances resulting in different fan Speeds. Its the serpentine that is the time-bomb. Ill bet most if not all traces are blown at a corner of the trace and not along a straight run.

Anyway:
Inspect the connector for signs of overheating or melting. Jeeps yj, tj, wj,...from this era are noted for having an issue. If you see it, there are other things happening besides the resistor.


Never look down on anyone unless you are helping them up - Jesse Jackson