CGT h2o/fuel gauges too low, after voltage stabilizer

[Ken]

Quoting Ti Kan <ti at amb.org>:
>
> Ken writes:
> > On my '86 Coupe GT, the water temp and fuel gauges read too low.  I have
> > replaced the voltage stabilizer/regulator with an untested new one sourced
> > from a list vendor.  It did not fix the problem.
> >
> > What is the next level of troubleshooting I can perform to fix this?  Do
> > the gauges themselves fail in some other way?
> >
> > I'm sure I'm supposed to test the new voltage regulator, which means I need
> > to buy some test equipment.
>
> The voltage stabilizer regulates the voltage to 10V, so you can simply
> measure with a DC voltmeter if you have one.  These stabilizers rarely
> fail by supplying low voltage, however.  They're usually working or
> not working at all.  I suspect that your fuel gauge problem may be
> a sender problem at the tank.  As to the coolant temp gauge, perhaps
> it's also a sender problem, or perhaps you are running thermostat that
> has too cold an opening temperature?

Shucks!  Yes, I was thinking that it might be two separate problems, running cold and a sender problem.

I wanted to make sure the gauges were working first, because I was curious to know what temp the car is actually running, and what would change once I flush the coolant and replaced the thermostat.  I have the parts to do that, so I'll just do that and see where it reads.

I may have a sender in my spare Coupe GT tank, which I'll check out.  I do have to buy a multimeter as well.

Had I known that the failure mode for the voltage stabilizer was no output at all, I would have saved myself the 7 bucks and letdown of replacing it.

Thanks Ti!

Ken