I just installed my Prosport oil pressure gauge last night and notice something weird. everything is hooked up and I put the key to the ACC position to test the gauge out and it works but it read 120psi without the engine even being on. I can't really start the motor right now because its not complete. I unplug the sender unit and it still read 120 psi. is this normal? Do I have to start the engine up first so it can actually read oil pressure? I thought if the engine was not running, it would read 0. anyone with experience please help.

-J

 

Double check your wiring, make sure you did not get the signal and power wires mixed up. If they are hooked up correctly then it could be a diagnostic sweep. Most electrical guages does that.

 

I triple checked all the wires and its correct. I thought diagnostic sweep would mean the needle go from min. to max. and back to zero? this sweep to 120 psi and stay there( max reading on the gauge is 150 psi). this is a brand new gauge. Do you really need an actual oil pressure ( engine running) for the gauge to function correctly?

-J

 

No you do not need the engine running for the guage to run correctly, once you put power to it normally it would do the sweep and back to 0. That is how it was with my old Defi.

I have a question, where is the sender mounted? Make sure it has a good ground. The sender sends out a - signal to the guage if the guage does not have a good ground then this might cause it to act weird.

 

I wired the acc, constant 12v, and ground to my aftermarket cd player harness. Would that be a bad ground source? and sender is mounted off a "T" from my oil feed line.

-J

 

wait till your engine is up and running then check it.
my friends oil pressure gauge does the same thing but once he turns it on, it goes to its proper position