Temp Guage and Otter

[TeGriffic]

The fans don't switch on in the Griff, not a problem as I have an override fitted. I suspect the otter switch just needs replacing - this problem started about 3 weeks ago. My question, if anyone can offer an opinion, concerns the temp guage which has started to play up only today, so there may or may not be a link between the two. If I accelerate hardish the temp guage flies up to 120 degrees and then comes back slowly to normal temp. There's no release of steam or loss of water so I'm thinking it must be electrical / sensor related.

[HeyAndy]

You may have an airlock - the symptoms of which are typical.

[RAW-SEWedge]

I'd rule out the switch first.

Take a small blade fuse and connect the two wires on the otter switch to it to complete the fan circuit. Turn the ignition on and if the fans run then the wiring is OK.

You could then remove the otter switch and put it in to hot water, and see if it operates. Think it should work at around 85dec if you have a thermometer to test. You'll need a meter or a test lamp connected to the terms.