GMC Envoy ignition problem

My 2004 GMC Envoy has a unique ignition problem. When I insert the key and turn the ignition, it doesn’t always start. I have to go through some machinations (i.e., turn the radio on and off; turn the fan on and off; put it neutral, etc) to get the car to start. Along with THAT issue, the oil and gas gauges go wonky. Sometimes the oil gauge will read 0 (yes, I know, that’s bad, but I check the oil) and sometimes it reads at max (ditto).

Our mechanic hooked it up to the diagnoser (what’s the proper term?) and it didn’t even identify the problems.

Any ideas?

It sounds like there may be a grounding problem to the chassis of the vehicle. I suggest you clean the battery terminals and the grounding to the chassis.