88 chevy g20 van instrument regulator?

[kc8adu]

got a freebie in that i got running.
but the oil pressure and battery voltage read high and coolant temp low.coolant temp not verified but i get good heat and fast.
battery voltage is 14.2v running.
oil pressure is 30 psi at hot idle verified with mech gauge.oil pressure on dash shows 50+psi
all body grounds are present and good.
i assume there is a regulated voltage source the instruments run from but no luck finding it.
haynes/clymer manual does not have the later model wiring.
anyone remember where this unit is?

 

[briarhopper]

It dont have a voltage limiter like Fords. The voltage limiter is part of the guage. 14.2 volts sounds about right. Maybe the temperature sensor is bad. If it is a 1988 it could probably use an oil and temp. sensor.

 

[RH+G]

Those sensors go bad on that vans all da time. Especially the oil ones

 

[kc8adu]

voltage reads 16+on the gauge.
a dvm reads 14.2
oil sender is new.
maybe the instruments got damaged somehow?
seems odd for all 3 to be way off.

 

[briarhopper]

I repeat>there is no voltage limiter on a Chevrolet. The same wire, I think it is pink runs from the guage fuse and feeds all three sensors. Try running another ground to the dash. One of the printed circuit screws should be a ground screw.

 

[RH+G]

Is this the gauge that has all three in the one large circle?

 

[briarhopper]

Yes, Actually 4, Fuel, Oil, Temp., and Volts.

 

[kc8adu]

voltage temp and oil pressure in a circle.
fuel is up and to left.

 

[RH+G]

More than likely that whole gauge unit got short-circuited and will have to be replaced. I have seen that happen before.

 

[kc8adu]

i am going to try a cluster from a scrap truck as a test.
grounds to the cluster are good .only thing i can see causing this now is a severe overvoltage in the past damaged the shunts on the meters.