I noticed that the dash icons did not light up when I turned the key on. The only thing on were the flashing light from the passive theft system and on the far right the air bag light. I started it and it seemed to run ok but the tach and speedo don't move. Also I noticed that the climate control lights up but the a/c compressor isn't coming on. I check the fuse box in the passenger compartment and the #7 fuse that the book says runs this was good but I put a new one in anyway. After i put the fuse box cover on, I was sitting outside the car with the door open and the key (off) in the ignition and the warning chime that goes off when you open the door started ringing. I turned the key on and everything was back working. I started the car and the tach was working. I looked a minute later and the tach was stopped at @500 rpm and everything else was out again. When I shut it off the tach stayed at 500 rpm.
Has anyone had to deal with something like this before?

 

Yes My mom has a 2005 Ford Five Hundred 40k miles And the back up lights were on when in park or driving. And the dash lights did not come on. They replaced the battery and alternator. And a week later the car won’t start now. It has been connected to the computer 3 times and shows no codes.