I have a 2004 ford freestar. When I push gas pedal my radio and heater turn off while my parking brake and abs light turn on. I push the break pedal and the lights go off and heater and radio start working. Wtf? Help!!!!!

 

Usually , but not always, a condition like this happens when there is poor or missing ground connection and the circuit will take the best available path to ground. Don't have a wiring diagram at this time to determine where the ground is for the radio /htr ,but it might be a good idea to confirm the grounds that you can see under the hood that go to the sheet metal are clean and tight.

 

The immediate grounds that I know of that will cause all kinds of GREMLIN problems are as follows:

1 ground behind the drivers side kick panel
1 ground connected to the A/C dryer/accumulator hold down bolt
1 cluster of grounds on the right side of the radiator support under the black plastic cover
1 cluster of grounds on the left side of the radiator support under the black plastic cover

Then you have the usual transmission/engine/fuse panels grounds. Heck, if you look and it's not corroded away, there is an underbody ground going to the muffler.