[Vwdiesel] Temp guage

[Sandy Cameron]

At 10:27 AM 19/07/2007 -0400, you wrote:
>
>This morning my temp gauge never moved. I drive about 63 miles each way and
scary to see it still pegged all the way to the left. Ambient temps around
70. So before I leave work today I'll check the sending switch with a meter.
So the question is which of the sending units are for the gauge 1) the water
outlet on the left side of the block or 2) the one on the front? 
>
>Do the gauges ever fail suddenly as last night going home all was fine and
I check the wires after I was on the freeway this morning and both are
connected?? I have to change my speedo cluster out soon as I have the oil
pressure buzzer issue, the trip odometer broke (487K) and now maybe the gauge. 
>


The sender for the gauge is on the front of the head, the yellow/red wire.
On later cars ( with the plastic hose fitting) there may be a plug with 2
wires, the yellow,/red, and a brown (ground). 

If the fuel gauge is still working properly, the voltage regulator on the
back of the cluster is ok, If it went west at the same time, it's the
regulator, a 3 legged TO5 power transistor-type package on the back of the
cluster.

You can check the gauge by grounding the yellow/red to battery negative...it
should go full scale.  In the post 88 cars with the 2 wires, the ground wire
has been known to go open, and cause the gauge to indicate cold.

If grounding the yellow /red does not cause it to move, You have wiring,
instrument issues.

If so, ground the yellow/red on the back of the cluster.If the gauge moves,
the problem is in the wiring to the engine room. if not, it's likely the
gauge.  I have a few.

Which cluster? 
The one with the gauge at top center, or the one with both gauges in the
bottom of the tach?

Sandy