when i start dash does light up also radio and heater motor inop after awhile they start to work and it does it all over agin any body know what is going on this is a 2001 gmc 4.8l sierra

Assuming you expect that the dash should not light up, as in: you are in broad daylight with headlights turned off, correct?

So . . . nothing at all from these? No lights no sound no nothing? If you left them on before the car got shut off etc. do they light up or make noise or anything when you start up again?

After about how long?

Where does it live?

How many miles?

Any trauma from accidents/disasters/floods/locusts/etc.?

Has it recently been in a lot of rain/snow?

Have you owned this vehicle for a while and it just started this or did you recently purchase this vehicle and it came with these issues?