a3 temp gauge!!!

having problems with my temp gauge.1.9tdi 2000.heaters ok. runs great.its not overheating.e.g when i got in the car this morning the temp was 90(it hadnt moved for 2 days).

anyway,can anyone tell me where the temp sender is?

i have been told there are two!!! is this correct?

thanks chaps.

I have a similar problem on my a3 2000, it runs fine, doesnt heat up or anything but the temp gauge is very unstable at all times.

Any ideas what it could be?

nigel