Temperature gauge reading max all the time

[cazna52]

After having done quite a bit of work in my engine bay my car now shows max on the temperature gauge all the time.

I have checked the wires on the coolant pipe where the sensors are located and all the plugs are connected.

I did run the car for about 1 or 2 minutes without coolant at one point when I was testing for spark and was so pleased that the car started it took me a few moments to remember I hadn't put coolant back in yet. I can't imagine running it briefly like that could have done too much damage.

It has coolant now but the temperature gauge just goes to max and stays there.

Does anyone have any ideas on how to test the sensor or what wires I should be checking to get the gauge working again?

Edited October 7, 2011 by cazna52

[andydclements]

If it was working and now isn't , my money is on a wire disconnected (the only wire) or the wire is broken internally.

[CHANGES]

Hi Justin,

Check the wire to the temp sender unit on the thermostat housing above the water pump, it is a non insulated spade terminal and may not be fitted and lying on the block so picking up a full earth making the gauge fully deflect to hot...

[cazna52]

Ahh, cool. I was looking totally in the wrong place. I thought the temperature sender was one of the three sensors on the coolant downpipe where the one that controls the fans is.

Should be easy to fix now. Thanks heaps for that.

[ramjet]

Justin,

Check the wire to the temp sender. I'm expecting it's come off near where you were working.

[Rich H]

What they said.

If you earth it to the block the gauge reads max, if you disconnect it should read zero.

That will show you it all works.