Temp gauge fluctuating

[gaxor]

Hi

Since my battery went completely flat whilst driving due to an alternator issue my temp gauge had been installed and fluctuating between 40 to 80deg

Any thoughts on what may have happened here

 

[revilla]

What engine? And what kind of gauges do you have (can you upload a picture)?

[BenF]

When I had this problem, it was because the connector to the gauge itself was loose.  Pressing on the back of the connector would result in a stable reading.  I solved the problem by bending the terminals on the back of the gauge out slightly, so there were a stronger contact between them and the connector.

[gaxor]

It's a 360S Duratec. The car is 6 months old

 

[moorsd123]

Had the same thing on my R400D and replacing the temperature sender cured the problem.

If I recall there are some posts in the archives that detail ways of testing if it's the gauge or not (I think you ground the wire that connects to the sender and the gauge needle moves all the way to the right??)

[Jonathan Kay]

Yes: with traditional analogue resistance-to-earth systems...

... you can test the gauge by ignition ON, disconnecting the signal wire at the sender, and then watching the gauge as you touch that wire to a good earth and to nothing.

... and you can test the sender by disconnecting it and measuring its resistance when it's cold and and when it's hot. 

But I don't know if a new Duratec has a digital system...

Jonathan