Hey guys, my Dad just bought a 2002 Ram 1500 4x4, and the fan switch only works when it is on high. Any thoughts on what it could be? Maybe just a new switch? He doesn't want to mess with it until he knows what the problem is...

 

It most likely needs a blower resistor. See if you have power going to the blower motor wire in any switch position other than high, a test light will work fine, if no light on the lower settings then check the input for the resistor the same way. If you have power going in to the resistor but not coming out then the resistor is bad. If no power is getting to the resistor then your switch is probally bad. I'll try to post some pictures later.

Will

 

Use this to check your blower resistor and switch.
[*]Disconnect and isolate the battery negative cable.[*]Reach under the passenger side bottom of the HVAC unit and unplug the wire harness connector from the blower motor resistor.[*]Check for continuity between each of the blower motor switch input terminals of the resistor and the resistor output terminal. In each case there should be continuity. If OK, repair the wire harness circuits between the blower motor switch and the blower motor resistor or blower motor relay as required. If not OK, replace the faulty blower motor resistor.
[ol][/ol]

 

You hit it right on the head priest... Blower motor resistor , $62 from the dealer = problem solved! My Dad says thanks for the tip. [sm=deal.gif]

 

Ouch!
I didn't think they were that expensive.
Consider replacing the blower motor too. Usually as the motor wears it starts to draw more current. The excess current is was causes the resistor to blow. Don't be surprised if the resistor goes againin 6 mos.

 

Only time will tell... Thanks 4 the head's up, though. Hopefully it was a freak occurrence

 

rabbler is right, I didn't think to mention it but you should definitely look into replacing the blower motor soon.

Will