Having got the erratic temperature guage, ie not getting up to 90 and staying steady, falling back to 0, going half way between the two etc., etc....

Replaced superceeded black sender unit 4 pin connector with new green sender unit four pin connector. All now working as it should be.

Part Numbers

S059919501A Green sender £30.86

N90316802 O Ring £1.17

S032121142 Retaining clip £0.49

Don't make the same mistake that I did and thought it would be the thermostat, I replaced that first and spent £20 unnecessarily, and therefore used two lots of antifreeze. Apart from the wasted time of course!!! The sender unit fools you, as it can start working again spasmodically and then plays up again.

NB. Boiled old thermostat in water in pan, popped open a treat. 10 years old and still looking/working perfect.