2005 Chevrolet SSR eletrical problem

I own a 2005 chevy ssr and for the last two days all of a sudden I've started having electrical problems on my truck but it's not been the same kind of problem every time. The first problem I had is I went to the store and when I came out of the store it wouldn't start but everything else worked ok. I had power for the lights, door locks, window, the top went down and then back up ok, so I figured the battery was ok. I let it sit for maybe 30 minutes and tried to restart it and it started fine and I didn't have anymore problems out of it for the rest of the night. The next morning the alarm went off for no reason just setting there with no one around it so I hit the button on my remote and that stopped ok. Later that day I went to take a ride in it and this time the top wouldn't go down. I did have the speedometer cluster customized about two weeks ago but it's run fine up until two days ago when the problems started happening. When I put the speedometer cluster back in, that I sent off to have customized by someone else, I didn't reset anything since everything on the cluster worked ok. Could that be why i'm having the problems i'm having now because all the problems seem to be electrical problems.