Temp needle ott

Post Wed Apr 03, 2013 3:39 pm

Hi everyone. I just uncovered and took my 1990 325i convertible out for the first time since santapod last year and noticed the temp needle when I turned the key on rockets off the scale!!!!
Engine is cold so what could be the cause? Sender unit, gauge? I don't know as I've never had this happen before...
Any ideas welcome
Thanks

Post Wed Apr 03, 2013 3:49 pm

I would check the wiring first of all as it wont cost anything.

I had a very tempremental guage that would bounce all over the place. In the end it turned out to be the instrument cluster after stripping and checking all wiring and replacing the brown sensor.

Post Wed Apr 03, 2013 4:33 pm

Unplug the C101 engine loom plug by the fusebox as a first test.
Does this make the gauge stay at cold?

Post Wed Apr 03, 2013 4:50 pm

Ok I will go and do that now. I have already pulled the feed for the brown sensor and it stayed down.
Will report back

Post Wed Apr 03, 2013 4:58 pm

Brianmoooore wrote:Unplug the C101 engine loom plug by the fusebox as a first test.
Does this make the gauge stay at cold?

Ok I disconnected the c101 loom plug and indeed it did not move .

Post Wed Apr 03, 2013 6:59 pm

trevski wrote:Ok I will go and do that now. I have already pulled the feed for the brown sensor and it stayed down.
Will report back

In that case, the sensor is faulty, or just possibly the wire to it was shorted to earth nearby, and unplugging it disturbed the short.

Post Wed Apr 03, 2013 7:09 pm

I am collecting a new sensor in the morning and I will post my results when fitted. Thanks so far

Post Sat Apr 06, 2013 9:42 pm

All fixed after the sensor was fitted

thank for all your help