2.3 Temperature gauge stuck even when the ignition is off.

[vince70]

Hi I wonder if someone can help, I've bought myself a lovely 1993 2.3 Audi cabriolet on Thursday and drove it over 330 miles back home with no problems, so it got a good test drive lol.
The only problem I have noticed with it was the temperature gauge is stuck just under half way even when the ignition is off,
It seems to run ok but obviously I would like to get it working again.
Would anyone have any idea if there's a sensor I should change and if so where I would find it.
Also does anyone think it was possible that I could have damaged the car in any way as I sat in traffic in central London, for ages so would the radiator fans still work.

Any ideas would be appreciated regards vince

[scotty33]

Hi,

Nice car for the weather we're having...

The sensor for the temp gauge is this MTFS:

SJM Autotechnik, Audi Technical Service Repair Information (http://www.sjmautotechnik.com/trouble_shooting/cooling.html#gauge)

If you can identify which wire is the one for the gauge, I suggest as a test you earth it with the ignition on, this simulates a very hot engine so should send the gauge to max. If this does not happen, I guess there is a fault in the wiring or more likely within the dash cluster:

Repairing intermittent water temp and fuel gauges (80/90/100) (http://www.ozaudi.com/forums/showthread.php/6131-Repairing-intermittent-water-temp-and-fuel-gauges-%2880-90-100%29)

That guide is a start, these cars instruments can also suffer cracked/broken circuit board, furred up connections etc, if you feel up to it a full once over may be a good idea while it's out?

[vince70]

Thanks scotty for the help,
i did the test which involves earthing the wiring to make the gauge move and the gauge only moved a fraction, also i earthed the other 3 pins just to make sure so I'm guessing it's the circuit board in the instrument cluster.
When I opened the cluster up I noticed someone had already attempted to repair the gauge and had damaged it, so I ordered a nos gauge and fitted that and it only worked once but before that its never worked.
So now I have ordered a solder pen, so now it's 3rd time lucky with taking the clocks out.

[scotty33]

Sounds like you are getting there, Good Luck!

[vince70]

Sounds like you are getting there, Good Luck!
Thanks a lot for all the advice you saved me a small fortune, I repaired the gauge a few weeks ago by stripping down the instrument cluster and cleaned up the the connections with a bit of wet and dry and used a solder pen on any iffy looking joints.
then I replaced the temp gauge with a nos gauge from eBay as the previous owner had played around with it and broke the adjustment screw, I even adjusted the fuel gauge to under read as I'm tight at putting petrol in my car lol.
it now all works spot on.
i even managed to repair my main beam flasher today as well with a bit of contact cleaner and fitted a new Sony head unit.
I'm just waiting to get the drivers seat back from the upholsterer, then the car is back to as new condition roll on next summer.