m750rider

1991 S4 auto.

I am not an electrical engineer so bear with me. I am trying to verify the correct functions of the cooling fan controls and specifically the temperature sender located at the bottom of the radiator, drivers side. According to the WSM and wiring diagrams I should be able to read the sender resistance at the fan controller, dependent on the coolant temperature, ranging from a few hundred to about 3 or 4,000. If I pull the connector plug and bridge the pins, or test the sender out of the car, I should see that same resistance.

Is that correct?

Thanks

WallyP

"If I pull the connector plug and bridge the pins..."

I don't understand this, but the rest sounds correct. I assume that you know that the controller lives under the passenger door sill cover.

m750rider

Yes, I know the fan controller is near the passenger seat.

I am asking about pulling the connector plug off the sending unit, then using a DMM to measure the resistance across the two output pins on that sender. Looking at the WD, I should get the same reading as at the fan controller if the wiring to the controller from the sending unit is good. This would also be a way to test the sending unit out of the car, right?

Alan

Yes (Wally's confusion was that "bridge the pins" means link them together - you didn't mean that...)

Alan