wacky dashboard

I have a 86 k2500 and the dash lights were working fine when i got the vehicle. I then hooked up plow lights and the lights were still working fine. But a while after the dash lights and all the gauges began going nuts when I would turn the lights on. The blinker also makes the gauges move. The lights on the dash also come on and go off randomly. Are there multiple problems here or do i just maybe need a new dash? Any suggestions.

Bad ground in instrument panel??