I swapped clusters now my oil pressure wont register

89 comanche 4.0 4x4 automatic
Well I found a gauge cluster and now I have m/gauges
the speedo works the battery is working the fuel gauge the temp but not the oil pressure.
I changed over the temp and oil gauges to merchanical.
any ideas on what to do and how to do it?
I had plum/tape on then I took it off, still not working.
the oil filter gets hot, not the new sending switch.
help

If I'm not mistaken, 89's need a new sender for a gauge, the one for the idiot light wont' work.

sorry I may have not mentioned but I did change the oil switch the old one was small and thin, the new one for the gauge has a big canister on it, then the signal tab on the end.
any other ideas?

thanks for your reply

You just need to make sure it is a presure sender not a switch. I have seen both in the big style.

Wow big differance
do u know a part number for the correct one?

thanks for the reply

Just to check the cluster out first, take the wire going to the sender and ground it. Check what the gauge says. Then take the wire and hook it to 12v and see what the gauge says. Can't remember which is which, but one should read 0 the other should read full scale. If that doesn't work, you either have a wiring problem or a cluster problem.

I did the swap a while back, and had the same problem. Oil pressure pegged at max all the time. I made sure to drill the parts counter guy for the right unit, for the gauge not the light. Turned out, that while wrenching the new sending unit, the plastic cover which also holds the wire plug slipped off slightly, from the tabs where it locks to the metal sending unit body (thanks napa). Inside, there is a prong which connects the variable resistor internal part of the sending unit to the plug, it had lost contact w/ the plug. I put it all back right and glued it. Works great now. BTW, its a 95 so may be slightly different w/ the RENIX units. I'm very satisfied w/ the new cluster, it really improves the driving experience over staring at the huge gas gauge, reminding me of my evaporating dollars.