Mk4 golf temperature gauge problem

[high country crow]

I have recently bought a 2001 golf. driving it home i noticed the temperature gauge never moved off of hard left of the gauge. after searching the internet i decided to change out the sensor but this didnt fix the gauge. again more searching and i started testing the wiring to the sensor. i found i had 5v at one of the terminals which i believe must go to the ECU but didnt get any voltage at the other terminal i believe should have 5v that feeds the temp gauge.

i thought i would test the gauge and just bridge the 5v from one pin too the other just to test if the gauge moves. It doesnt. when doing this it takes the voltage back to only 1-1.5v. So now i'm thinking i have a damaged loom as i'm not getting supply voltage too the sensor and when i bridged i think it went to earth and that is why it dropped the voltage? Someone please correct me if this train of thought is wrong.

i followed the loom back to a connector located under the battery box but was unable to get it apart and was to scared to force it and damage the plug. So my question is, is that the correct connector to test or is there another spot i can check for continuity and voltage for the circuit.

Thanks

[Umai Naa!!]

Have you ruled out a bad thermostat?

[high country crow]

i have not looked at the thermostat yet. but the car seems too warm up ok and the coolant hoses get warm. heater works well. anything else i should be looking at?

the thing that worries me is the 0v on the plug that should have voltage.

[jmcc]

Sounds like a thermostat, it alsi sounds like ur applying alot more electrical know how here than most though so maybe you're right about the sensor.

[MK4Mishy]

I'd say thermostat too. Happened to ours too, Replaced it and back to normal now.