Instrument cluster diagnostic test (1994 90S)

[Huw Powell]

> I've been informed that on a 90 V8q there is an instrument cluster
> diagnostic test which can be invoked via a simple DYI trick. Does anyone
> know if a similar trick exists for the 1994 90S? I'd like to check the
> performance of my temp gauge without having to remove the inst cluster.

Well, I dunno what the V8 folks are doing, but usually you can test the
temp gauge by substituting a couple of fixed resistors to ground in
place of the temp sender.  There will be some value in the manual that
should result in a "normal" temp reading, and maybe one for the cool end
of the gauge and one for the overheat end.

A dead short will peg the gauge, I don't think you should do that for
too long.  It's ok for long enough to watch the gauge til it stops
rising, though, since there is still the resistance of the gauge
movement in series with the regulated voltage that drives it.

The same regulated voltage usually drives the fuel gauge, too, so if you
see aberrations on both, you suspect the regulator.

Disclaimer - this info is based on learning from cars at least a few
years older than yours.

--
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/