Climate Control

Temperature Sensor Troubleshooting

> Does anyone know how to determine that you have a bad temperature sensor -
> exterior and/or interior? I understand that you can measure resistance across
> the two leads of the exterior sensor, but do not know the proper number of
> ohms. This sensor has a pair of wires going forward, but I don't know where
> they go. They are in a gray sheath. Is there a place where I can find a
> connector for these wires without pulling the wheel well skirt again? Would
> the ohm reading from these two leads be the same as at the sensor?
>
> Any clues about determining for sure that the temperature control unit in the
> center console is bad?

Either case the sensor is a simple thermistor. I forget what values I read off mine but it should be about 1000 ohms to 2000 ohms. But don't fret if its outside that range a bit.

The most important thing is that you should be able to *change* the measured resistance by blowing on the sensor. 50 or 100 ohm decrease would be typical.

While the above will not prove the sensors *good*, a zero ohm or megaohm reading would prove it bad. As would be the case if you can't get the reading to change by warming the sensor.

If the component was bad, I'd be tempted to take a DigiKey or Mousercatalog, buy a bunch from them (about $1.00 each) try to get my hands on a good sensor, then figure out which one from the catalog was the best match.

Hmm, I might have a spare ugly chiped working inside sensor laying around I could measure without taking the car apart. Will look and let you know if I find it.

'83 928S