94 IDI Turbo, ever since i got it the cooland and oil pressure gauges dont work, the oil pressue will move around a little bit randomly, so im wondering if its a gauge cluster issue or if both sending units are bad, rest of the gauges work fine, can anyone tell me if this is a common problem and where the sensors are for the 2

 

figured id give this a bump, still have the issues with the 2 gauges, truck runs fine.

 

Here's a picture of the rear of an IDI, the oil pressure sending unit is in that yellow circle:



Key off, engine off, remove that wire and ground it. Turn the ignition on, (no need to turn the engine on.) If the needle on the gauge goes to the far right then the gauge itself is okay and the sending unit is the problem. If the gauge doesn't move or not all the way there is something wrong with the gauge itself or the wiring.

This picture shows the temp gauge sending unit:


The test for that is exactly the same as the oil pressure gauge.