Thread: Temp gauge reading high

I would replace the voltage reg or see if you can borrow one

Adam

The voltage regulator may need replacing, but more likely, it just needs its earth connection fixing! (In the Series 3 it is mounted on the back of the speedo, but I'm not too sure just where its earth lead goes to. )

John

I'll back the voltage regulator or a voltage drop when you turn the lights on from the key/fuse block. replacing the fuses if they are old and cleaning up the contacts sometimes helps out.

earth lead is only about 5inches long earths out on one of the speedo mounting posts should be 3 wires there very easy to find just undo the 2 screws holding the facia on and pull forward you can see them and the regulator behind the speedo

Originally Posted by THE BOOGER

earth lead is only about 5inches long earths out on one of the speedo mounting posts should be 3 wires there very easy to find just undo the 2 screws holding the facia on and pull forward you can see them and the regulator behind the speedo

Yes, but you need to make sure that this group of wires is actually connected to the chassis reliably!

The high reading when the lights are switched on strongly suggests that the regulator is earthing via the instrument light bulbs and parking light filaments - and the voltage of this "earth" rises when the lights are switched on. I expect the instrument lights are dim as well, and that their brightness changes when the ignition is switched on.

John

Yep there is a second earth will look to see where it goes in the light tomorrow, arnt all series dash lights dim

Originally Posted by JDNSW

Yes, but you need to make sure that this group of wires is actually connected to the chassis reliably!

The high reading when the lights are switched on strongly suggests that the regulator is earthing via the instrument light bulbs and parking light filaments - and the voltage of this "earth" rises when the lights are switched on. I expect the instrument lights are dim as well, and that their brightness changes when the ignition is switched on.

John

I completely rewired mine a few months ago, pretty sure the voltage stabilizer has an earth to one of the speedo posts then an earth from there to the steering column.

Thanks for all the advice, will pull it out in the weekend and have a look. Instrument lights definately dim, just assumed that was another gift from Lucas...