Water temp gauge

[roy_allen]

I have mentioned this a few months back but now I`m getting round to sorting it out i need to ask the following:

Basically my temerature reading doesnt move. I have taken the sensor out and tested it using some boiled water and the resistance changes as it appears it should. The bible says to read the resistance at the ECU, but I`m not happy messing with it. I havent yet tested the gauge and ive had a bit of a look to see how i can get to the back of it and I cant. My question is, how do I get to the gauge to test it and how do you test it?
Also could the sensor still be the culprit even though it seems to be working?

Any ideas?

Roy.

[GreenV8S]

Are you sure you have the right sensor? I expect you'll find the ECU water temp sensor and engine temperature gauge use separate sensors. You should have found the gauge went to min or max when you disconnected the sensor, which would confirm you have the right one and the wiring is intact.

[roy_allen]

Next to the sensor that I previously tested there is what looks like an earth stud with just one wire coming from it. Is this what you mean?

So the sensor that I tested is solely for the ECU and the 'other' one is the one I should be looking at?

Roy.

[roy_allen]

Hazzah!!! I found and repaired the fault.

After disconnecting the wiring to both of the sensors i noticed that the single wire leading to the sender was a little floppy. After removing all of the tape i found a resistor (which looks to have been used as some sort of calibration) which had decided to come apart at the leg. After removing this resistor and wiring it all back up, the gauge is working fine.

So now with the resistor removed the fan comes on when the needle goes just above the mark above 90 (instead of coming on when the needle is over the number 90) which to me is how its supposed to be as the mark above the number 90 must be the 90 degree mark.

Roy.