Hey all,

I wanted to see if anyone had the best way to test the water temp and oil pressure gauges. Mine are stuck and I'm not sure the best way to test to see if its the sensors on the intake and engine, the wires, or the gauges themselves. Is there a way to test each one independently? Thanks! -Ross

 

You can measure the temp sensor resistance at ambient and then putit in some boiling water (212F) and measure the resistance. It should change. Here's what I got a long time ago for mine: 600 ohms @ amb, 190 ohms @ 160F, and 100 ohms @ 210.

The oil pressure sensor would be a little tougher. You would need to get some fittings to adapt it to an air compessor and another good gauge.

 

One quick way on single wire gauges (senders) is to ground the wire going to the sensor. that should pin the gauge full. If it does then you know the wire is good and a good chance the gauge is good. The oil gauge should be a mechanical gauge , meaning it is just an oil line going straight from the engine to the gauge. Best test is to get a chepo gauge kit and plug it into the engine side where the old line comes out. Mechanical gauges don't usually go bad.

 

Hi C3er, and welcome to the forum.
Ifyou disconnect the wire to the water temp sender and hook it to a ground, then turn the key on, the guage should go all the way to the right. If the guage works then the sender is bad. If you still get no reading then the wire is broken or the guage is no good.

Older vettes had a oil line that brought oil pressure to the guage, others had a pressure sending unit at the rear of the block, what type do you have? PG.