MIL's car has decided not to blow air into the cabin at all. It has 0v at the motor connector, but the resistor is not the usual collection of resistors, as the AC has auto mode and is variable. Only 3 pins and some electronics. How do I test that with a multimeter?
It is rather a module that takes pwm signal from ac controls, and varies the voltage to the fan. Mk3 golf for example also has 3 pins, one small wire gets positive voltage low current that controls the fan, another thick wire gets power ground, and the last thick wire goes to the blower. The positive power wire goes to the blower. So you can test for a switched positive or negative power wire to the blower, and the other power wire that powers the spikes module. The small wire that controls the blower best is to use an oscilloscope but you can try to use the multimeter while you set the blower speed high to low and see if the voltage also varies on the thin control wire. Did you test the motor with 12v? Is the fuse that powers it good?
Cheers David, that's rather what I feared! I have the motor and resistor pack at my house now, hopefully test the motor tomorrow and go see the MIL to check the fuse and relay also.
