dancing temp' gauge

[Cloggy Saint]

It's been doing it for years and it's time to sort it out. The nut on the back has been tightened and I'm fairly sure it's not the brown sensor as if I give the dash a few good thumps it settles at normal running temperature for a while before jumping around again. Should I just replace the gauge?

[Bristol_Jer]

Isn't this also a symptom of a SI board thats starting to play up?

[Rtaylor2208]

I've been in the same situation with my cab, so far I have replaced the sensor, had all the wirin checked out by an auto electrician. I've got a new set of clocks there to see if it finally fixes the problem.

Is yours the same issue as mine, only does it once warmed up?

[steve_k]

I'm in the same boat as cloggy saint, but I did replace the brown plug.

so if the SI battery's are on their way out how do you go about changing them??

[Grrrmachine]

You have to remove the dash cluster, open it up and look for a pair of batteries sitting on the circuit board. There are two types of batteries used, so you need to open the cluster before you can order replacements:

http://www.e30zone.net/e30zonewiki/inde ... _Batteries

[Cloggy Saint]

Mine only does it when warmed up. I wouldn't think it was the SI batteries, it's been doing it for literally years, if the batteries were going to fail I'd have thought they would have done so by now.

[Grrrmachine]

That's the thing when things go faulty; they don't work like you'd think they would

My SI batteries were duff when I bought the car three years ago; the mileage gauge would swing around all over the place. But they only got bad enough to affect the temp gauge last month.

[Rtaylor2208]

Not that this helps to solve the problem but its good to know I'm not the only person with the same problem. Now if it will only stop bloody raining I can get the new clocks fitted and take it for a drive and post back if its a fix.

[daimlerman]

Swapping the SI board fixed my dancing rev counter and fixed strange temp gauge readings.

Remember that the SI board takes information from both rev counter and temp gauge to determine when to put green lights out.