I have a '97 F150 4.6L with an electrical problem where if I turn the headlights on I have no dash lights or turn-signals. The only dash lights that work when the head lights are on is the brights, check engine, and turn-signals (which are constant). Also if I try to turn on the air, the fan does't blow and I lose all of the above. I believe this is a grounding issue. How do I fix it? Thanks

 

What work in that area has been done recently, radio install things like that? It could be caused by some hacker installing something.

 

Got it fixed. Turned out the common ground between the two had rusted off. Re-wired and re-grounded fixed the problem.