I was driving home tonite, had the heater cranked full blast, and all the sudden my dash backlight starts to blink, my speedometer bounces up and down, volt gauge goes crazy and my radio blinks on and off

I shut down all the electrical things, wipers, radio and heater fan and it stops, so I turn the heater back on and it does it again
tried this several times and it kept doing it, but by the time I got home all worked fine

This is in a 94 p/u

Does anyone have any idea whats going on?

 

Wild guess, but I'm thinking your fan is drawing too much power. Maybe time to upgrade the alternator?

 

I've never had an issue with the heater fan before and all the parts are factory

I'll try changing alternators when I get the chance, its given me troubles before


Just don't really understand why that would make my gauges get all crazy