Chrysler Repair: Interior blower only works on high., intake plenum, pin plug

Question
IT only works on high fan someone told me it might be a resistor? please help

Answer
Hi Jim,
You didn't mention the year and model so I can't be specific but what is likely broken is a module called the resistor block, which is what divides the voltage so as to reduce the fan speed when you have different switch settings. It can either be in the blower duct next to the blower or it can be in the air intake plenum just below the windshield. It has a 5 pin plug and a couple screws that hold it in place. You can get a replacement for around $20 and when installed will fix your problem. Check that the resistors are not touching one another before you insert it.
A dealer can show you where it goes in the their parts diagram or write back with specifics and I can tell you. Another way to find it is to trace the wires that power the blower motor to their source.
Roland