[Vwdiesel] VW instrument cluster problem

[Roger Brown]

Caleb Van Dyke wrote:
> I have a 1981 Rabbit pick-up with the diesel, and I am having a strange problem with my temperature and gas gauges. Every so often, the temperature reads about 3 notches higher, as well as the gas gauge. Then, for no apparent reason, goes back to where it was. This has me wondering if there is a loose connection somewhere, a voltage imbalance or surge, or ???
> I have noticed in my Haynes manual that in 1982 VW put some sort of a voltage controller in their dashes. I do not see this on my dash set-up, so I'm assuming it wasn't avaiable in '81.
> 
> Thanks for any help.
> 
> Caleb

The voltage stabilizer or regulator is a little 3 pin IC on the back of the cluster, 
visible on the far left center of the photo below:

http://www.4crawler.com/Diesel/CheapTricks/Tachometer/Images/tach_08.jpg

Might be that component is going, it normally holds the voltage at the cluster around 10 
volts, but if it let the full 12.x volts through, you would get more current flowing 
through the resistive sensors and more current = higher reading on the gauges.

-- 

   Roger