Sensor ID? M50

[repenttokyo]

What is the sensor on the passenger side, top of the radiator, on an obd-i m50? I just noticed that mine is disconnected, and the 3 prongs that plug into it are hanging beside it. I can't remember if it was like that when I bought it, so I am hesitant to re-attach it if it's not necessary.

[E34-520iSE]

Any chance of a pic?

[Dave M]

Its a temp switch. I thought it was related to AC function, but could be wrong. As I deleted my AC, I'm not sure what the consequences (if any) are of leaving it hanging ;) Feel free to re-attach it, can't see it harming anything.

Dave

[colo525i]

It is a coolant temp switch to turn on the electric fan. Sort of a fail safe for cars with a/c. If the coolant temp gets past 100 or so C it will come on, past 110 or 115 it should kick to high speed. If your electric fan comes on all the time, the switch has failed in the on position. I'd leave it plugged in, if your clutched fan fails, the electric one should help.

[repenttokyo]

cool. I had some abortive work done on my ac earlier this year, and the ac fan is frozen solid in place - is this the fan that relates to this sensor? It would explain some things. thanks for the quick answers guys.

[colo525i]

Yes that's the fan. The magnets like to come apart and seize the fan, mine was like that when i bought the car.