Chrysler Repair: 2002 Chrysler Sebring Sedan: blower motor fails, blower motor resistor, infinite ohms

Question
Hi Roland,

My car hot/cold cockpit fan works only in 3 and 4 speed, When it is at 1 or 2 speed there's no action at all. I've looked up at the relay box but haven't found anything.
What can it be the problem?

Answer
Hi Roberto,
Most likely it is the 'blower motor resistor unit' (or sometimes called 'block'). It has three resistors in a chain, and two of them have probably burned out. You will find it on the front of the h/vac unit under the dash. It has a 4-wire plug/wires of which two go to the blower itself located just to the right of the resistor unit (turn it on to locate the blower motor). So look for the wires that run from the blower motor to the plug and you will find it. It is held in the unit by two screws and then you pull it out of the housing. If you want to test it use a continuity- or ohm-meter. To measure it:
Hold the unit with the key side facing up. The pin on the lower left is the common test point. Measure between that pin and each of the other three. You should get a finite value for resistance or continuity to each of the other pins. You will probably only get a finite reading to one of the three pins, the other two will be infinite ohms (or no continuity in the circuit) which would explain why you don't get speeds 1 and 2. You might just be able to look at the resistors and notice that two of them are damaged.
It should cost less than $50.
To access the unit, just remove(or depress?) the "stops" on either side of the glove box so that it drops all the way down and you can then see the h/vac proper, and find the resistor unit for removal.
Roland