Greetings. I changed my leaking gaskets about a year ago and noticed some gauge problems. I rarely use the vehicle, so it got put on the back burner. I have two issues that are as follows:
1. My oil pressure gauge needle now works backwards. With the engine off, it is offscale and moves downscale when the engine is running. I disconnected and reconnected several electrical connectors when doing the work, but I remember all of them being "keyed", so I don't think that I installed a plug backwards. That said, the gauge simply acts like the dc polarity is somehow reversed.
2. When shutting down my engine, the temperature gauge needle drops off as expected. Within a few seconds, the gauge spikes to above 220 degrees and stays there. Once I remove the ignition key and open the door, the gauge drops off again and stays there.

I cannot be sure that the work on the LIM caused these issues, but neither was present before I did the work. Thanks in advance for any thoughts or suggestions.

 

Don't have much to offer, other than in my experience, every gm connector can only go back to the right plug, and be plugged in the right way. Every sensor, etc, is unique (can't plug the map into the tps, for example) and they won't go on reversed.

 

Thanks for trying nonetheless...
I am not even sure where the oil pressure sensor is located or if I even disconnected the plug for it when I replaced the LIM gasket set. This one has become quite the mystery.