bluenight44

Hi all, I'm AL, just bought a 75 vette, 350, auto, oil pressure pinned @80 with vehicle on or off, no reading amp or temp, horn doesn't work, interior lights work when open the pass side only, radio works, clock doesn't work,runs great, no smoke, any ideas? TIA

Big2Bird

Start with the fuses under the dash, drivers side.

pmr2000

Would that be bad sender? (thats what it did on my C5 when sender was bad)....

jimvette999

I believe there's an issue at times with the ground on back of instrument cluster at console...specifically the ground on the amp meter..I think. The interior light issue is likely unrelated and tied to the switch at the door jamb.

Here, courtesy of Forum sponsor vendor Willcox Corvette https://willcoxcorvette.com/

worship79

For the oil pressure I'd start with the single wire coming from the sensor; mine was barely hanging on which also resulted in an continuous 80 PSI reading.

Re-soldering the wire fixed it. Getting the clip out of it's rubber housing was a bit of a fiddle.

0Willcox Corvette

If the gauge were missing ohm input it would read past 80 lbs and just to the top of the right hand rivet.. so I don't think this is your issue.

Pull the wire off the sender and ground it out.. the oil pressure gauge should go to 0... If it fails this test then I'd look at the gauge as being the issue.

the oil pressure gauge on your car is exactly the same gauge as a fuel gauge with the exception of the dampening fluid. Both work on the same scale 0 - 90 ohms with the only difference being the dampening fluid inside the gauge. The fluid in a oil pressure gauge is thinner than that of a fuel gauge which allows for a faster response time.

So use this chart and just pretend the gauge say's oil pressure instead of fuel... (until I can make a new one for oil pressure gauges).

Willcox