W126 - twitchy coolant temp needle

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Active Member
Jul 22, 2009
Southam, Warwickshire
1992 190E, 1989 500SEC, 1968 220/8
The coolant temp needle on my SEC has all of a sudden become really twitchy. It will sit at the correct temperature for a while and intermittantly flick back to zero. Im guessing its the sensor, a connector or the insrtument cluster. There are 2 or 3 sensors near the water pump, any ideas which one goes to the cluster?
Temp gauge sensor ...

On my 124 it was the sensor with only one terminal, i.e. it makes it's connection via earth (0v via the engine) and the single terminal on top. It was near the other temperature sensors (4-pin for engine management and 2-pin for aux fan) by the water pump.

And, yes, in my case the single cable to the flying lead connector was dodgy and fell off. I had to solder it on and now all's OK.

Bon chance.

I have a 420SE here for breaking just now - let me know if you need any parts - there's a bit more info over on the 'other Mercedes' section of the 190 forum .

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