1993 f150 xlt 3.0ok this is crazy problem..head light work good but i can't turn on windshield wipers with lights on..work slow when lights off..ok more this all happened like at once the problems. I lost my power windows and interior lights with this!. It starts fine. When I turn lights on I loose n the dash lights and my signal lights inside dash stay lit! .I also lost my heater fan period.. won't work at all..HELP.. LOL

 

It is after 6 PM , If you have not found and fixed the problem ,
suggest you find and clean the ground wire from battery negative terminal or engine block that provides the ground to the sheet metal.
Always appreciate when you provide us with an update, thanks.