300tdi Coolant Temp Sensor

the temp guage on my 300 went a bit erratic today. It was reading properly, then it went to Zero for a while, whilst stationary, then back up to normal temp once driving again.

I took off the wire and shorted it out againt the block and the guage went up to red hot - which is what I would expect. Normal levels of coolant in the expansion tank.

This suggest to me that the senders knackerd... but could it be anything else in the mix like a sticking thermostat or even something more sinister??

My 300tdi started doin a similar thing yesterday.. Cept its goin from normal to red hot, then back again. Have checked me fluids an all fine. So am hoping its nowt serious and me temp guage is just bein spacky. Me speedo wer going mad today aswell.. it was jumping from 30mph to 70mph. I was only doin 25mph.. I know Land Rover don't make the most accurate speedo's in the world but ffs..! Mebbe my two problems are linked??

fink there's a voltage regulator on yer dashboard somewhere, which can cause things like that to happen when it goes tits up.

Ere Trew, yer very helpful and clever. Thats twice today . Thankyou.