The blower motor only works on high. I've got the controls out of the dash. When I use a jumper wire to run fan, still only get high to work. Could it be the resister block for the blower motor. If so, is it located next to the blower motor.

 

Could be the speed control switch, resistor set (usually attached to the blower housing somewhere to get airflow across them to keep them cool), or a fuse.

I don't think the Ram does (I don't think, but could be wrong), there are some vehicles that use 2 fuses for the fan. 1 fuse controls the lower fan speed settings, and the other controls the higher fan settings.

 

If it only works on high then it is the resistor set that should be on the blower motor housing after the fan and before the heater core / evaporator.

 

99.9% sure it is your resistor since you blower is working on high. The resistor cost me about $70.00 here at my local dealer.

 

I had a fan switch fail before, and it only worked on Hi. Ne resistor set didn't solve the problem.

 

The 3rd gen trucks (at least my 03 model) dont have two fuses to control fan speed. The the fan/blower will have a constant +/- 12.6v power supply to it when the ignition switch is turned on. The resistor is linked into this power supply and controls the fan/blower speed. If you have a buddy close by to try his resistor, I bet this will solve your problem. It only takes a few minutes to change -2 screws and a quick disconnect plug.

 

Thanks for the quick responses.