Electrical problem in dash

Alright, so a weird thing happens randomly in my lude. Starting is fine, mechanically perfect, runs normal. After about 20 minutes or so of driving, the speedometer and tech will start to drop to 0, the fuel/temp reading will flicker on/off and the clock will go dark. It happens moreso when it's at idle, but it will do it when it's running at any speed too, just not as much. Also, when the headlights are on and AC is running, the problem gets really bad, it happens constantly when they're running. Less if say the headlights are on and not the AC, or visa versa.

I got the alternator and battery checked; both are fine. He told me to clean off the positive and negative terminals, the connecters to the battery too. I did that, they're pretty clean now. The problem still exists. Not sure what to do now, the alternator is charging at 14 volts if the number matters.. he said that's fine.

Check that serpentine belt again (the belt that loops around your alternator, power steering, and.. gah I have forgotten the third). Specifically check the tension and the grooves, they probably are slipping.

You May have a hot wire under the dash that is grounding, unfortunatly this could be very hard to find.

Yeah, well it started to happen a little bit after I got an alarm put it. I'm probably gonna take it back to those guys and tell them whats happening. I had to go back once before because the alarm when on the fritz one day, the owner said sorry because they installed it very sloppy. So it's probably their problem.

May be a ground wire, but probalby from that alarm install.