306 temperature gauge T reg meridian and cooling fan issue

[Rustington]

Hi ,Im new to the forum ,brought a T reg 306 (it`s a 1.6 meridian) the other day but the temperature gauge is not working at all ,and on checking it looks like the fan is not running either to cool the engine .
I have read a few forums and have tried unplugging the brown plug which does make the fan go into auto mode and come on.
Could i have a problem with the brown and the blue sensors ? i thought the blue did the dash gauge the green does the ECU and the brown does the fan .Any Advice would be excellent thanks!!!

[spider]

Welcome!

The colours are about right as far as I remember.

The brown one (assume you have aircon?) is the Bitron sensor. If that's unplugged the fans should come on within 10 seconds as it sees "no signal" as "overheat"

Without the dash gauge working its not easily possible to tell without other instrumentation if it is too hot. The normal running temp is about 80 and the fan comes on at 90 typically. With the AC on a fan will run all the time regardless of engine temp.

Does the engine start and run OK from cold ? (more starting than running) that would indicate the green sensor (ECU engine temp) is correct and its providing the correct mixture for a cold start.

Is the blue sensor a single pin ? If so get an assistant to sit in the car with the ignition on (engine not running) and unplug the blue plug. Momentarily earth it (a second or so no more really) and have the assistant watch the temp gauge for movement OR sometimes a red warning light, it might be at the 'hot!' end of the gauge or it may be on the left side of the panel with that light cluster.

Sometimes the gauge itself can work a bit loose as its held in by nuts. Gently (as in little finger only) tap the instrument panel near the temp gauge area to see if there's any improvement.

EDIT... Edited slightly for clarity.