Temperature Gauge playing up

[rogercw1]

Hi there,  have any of you got some ideas for intermittent problem with engine temp gauge?

Sometimes (from yesterday most of the time), it reads anything from 90 to over 110.  AND it is NOT overheating. 

Disconnected the wire to the sender - no difference.
Petrol gauge working ok as they use the same regulator.  General thought is that it is the wire shorting to earth, but I wondered if any experts out there had a better explanation?

thanks

[ian]

clean up the connections on the thermostac housing