wierd electrical problem

[chevytom03]

I have a 2003 chevy silverado with 140000 miles, my problem is that my ABS / Parking light came on the same time my radio went dead and my heater quit working , i checked all fuses and most wiring harnesses . cant find the problem any ideas. it happened once before and after a couple of days it went away . Please anyone with a answer .

[ChevyTech77]

Poor battery connections, poor ground plane or faulty ignition switch would be my three guesses.