Temp gauge problems!
 

The coolant temp gauge on my 1989 760 V6 is refusing to move off the stop. The car has never been messed with, has 74,000 miles and 1 owner before me.

I've just replaced the gauge sender unit on the back of the engine block, but the gauge itself is still dead......I've given the top of the dash a whack too, in case it was stuck and it didn't make any difference.

My questions are:

1) If I remove the offending gauge from the cluster, is there any way to test the gauge for function my applying a signal to it directly? If so how....??

2) If I get a 2nd hand cluster, will any 740/760/940 temp gauge fit, from any engine type, or does it specifically need to be from a 760 V6

3) Other than the gauge being kaput, is there anything else you guys would suggest I try, the wire doesn't appear to be damaged anywhere.

On mine, with ignition on, the coolant sensor plug has a 5v signal feed.
I wouldn't have thought things have changed too much since yours.

If you remove the plug from the sensor and bridge the two connectors on the lead does the gauge move?

On the basis that it is a cluster made by Yazaki (most, if not all later 760's are) a gauge from any VDO cluster will not fit. I assume that a Yazaki gauge from a 940 (at least earlier ones) will fit, but if no further replies to this thread you will have to check it visually.

Forrest- It never occurred to me to try that......good idea! I'll try bridging the connections on the plug and see if it moves....I take it if it moves then the new sender is faulty, if it doesn't move it's the gauge? Bridging the connections won't damage anything will it?

Bob- I assume it's the Yakazi version...I was hoping a VDO gauge was a straight swap into my cluster.....I'll pull the cluster at the weekend and visually check it out, but I'm 99% sure it's a Yakazi unit.

Look at the lower trip odometer .. if it's got divisions in the face plate between the every number comprising the hundreds and tenths it's a Yazaki. If not it's a VDO.