sometimes the power goes off on guages and air conditioner compressor

If memory serves, it's early though, you need a tack reference for the compressor to remain active. The instrument cluster and connections on the circuit that feeds it would be a good place to start. There will be some testing involved as well as everyone's favorite... trim work. The connections might have corrosion, clusters do have issues too. You'll want to have it diagnoses to prevent chasing ghosts. Electrical is not fun as it is, add years of climate, unless you're familiar with the electronics in the vehicle, I suggest you enlist help and a failure can be proven to save you time and money.