I bought the car back in may 2012.. its an IROC-Z...i realized then it had a v6 cluster with the v6 tach in it... the tach was reading about 500 rpms faster (because it was not the right tach)... however the oil psi gauge WAS working.. why did my IROC-z have a v6 cluster? idk.. maybe my car used to be a parts car and the guy put whatever cluster in he could find to pass inspection.

Today, i put the new cluster in.. a v8 cluster... the RPM now reads correctly... however the oil psi doesnt read at all...

im thinking this is because V6 clusters need a different oil psi sending unit to work a v6 gauge... vice versa with a v8. so maybe if i put a v8 oil psi sending to unit in, it will read.. Am i right? or is the gauge shot?

 

Same sender unit used on all.
Quick check , touch the OP gauge wire to ground.If the gauge moves you know it is fine and the sender is faulty
If it doesn't the gauge itself ( or wiring to it ) is suspect

 

Not completely true,.......From 82-88 there is a specific sending unit for V6 cars and another for V8 cars. (canister type sending unit) I'm not sure about the 89+ 3 wire OP sending units.

A cluster swap is pretty much 'Plug-&-Play'; if the gauge was showing a reading with the first cluster, it should be showing a reading with on replacement cluster.


Could be a bad OP guage, but I'm betting the printed circuit on the replacement cluster is bad. After 20+ years of use the printed circuits on these clusters are becoming a VERY common problem.

 

I hooked a battery up with some wire, used it on the v6 gauge and the needle increased.. i used it on the v8 and the needle only decreased.. could that be a sign the v8 one is bad? how would i go about fixing besides replacing?

 

Update, ok i swapped a tab tht was on the back of the v6 oil psi from the v6 tach and put in on the v8 tach.. it increased this time, but when i plugged it in my camaro, and started the car, it stayed at 0. even when running

 

anybody? bump?

 

Have you checked the printed circuit yet ?? There's a very high probabability that it's bad. Could also be the gauge itself and it could be the circuit board on the tach too.

You should simply leave your original cluster in place and install the replacement V8 tach into it. If everything else was working fine - all you need to change is the tachometer. You know the original printed circuit was fine so if the OP gauge doesn't work in the original cluster than the tach/circuit board/OP gauge is bad.


Use the original cluster
Install the replacement tachometer into the orignial cluster
Connect everything
Disconnect the OP wire # the sender.
Turn the key to RUN.

The guage should peg to the high end of the scale.

Did it work ?

 

FIXED IT

i decided to remove the oil psi gauge out of the v6 and put in the v8 tach. had to drill out the rivets and pry off the gauge needle with a fork. replaced the rivets with 0 size nuts and bolts. runs great now!! thanks for the help everyone!!! i realized the oil psi unit on the new tach i got was bad.