heater when on hi will cut out but only on hi ! sounds like the controll pannel but ive gotta ask.. now radio quits working but radio lites still stay on . again sounds like a unrelated problem but hopeing some one here could shed a lil lite on this for me . how could i forget i have wiper motor problems as well .. a big thank you to someone for helping me

 

Always check the fuses to make sure they are not rusty or corroted.

Sounds like you could have a loose ground or short, that feeds the circuits. But they could be unrelated to.

But if the fan works fine on other speeds then the normal circuit seems to be working.

If you can get to the fan/blower motor then you can check the voltage when the switch is on high to determine if you have a bad switch or blower motor.