Lights go out when heat goes on

[Stevens]

Here's the scenario:
Last week, the stock stereo display would flash and then go blank. It would come back on if the headlights were turned on.
Yesterday, the heat was working great around 3pm.
When I got back in the truck at 11pm, if I turned the vent position dial from off to anything else, all of the dash lights turn off and it even turns the turn-indicators on the dash solid, plus the fog lights turn on.
Today, It the ac and heat work fine, but when the blower dial is in position 2 or 3, the stereo display goes dark. If I turn the headlights on, it doesn't go dark.

Uhhh... I'm guessing bad stereo, dial, maybe relay???
Any suggestions?
Thanks,
Stevens

 

[pcohenchicago]

Sounds like some serious electrical issues happening there... No suggestions other than letting Ford take a look at it.