88 Silverado dash lights going crazy

i have an 88 silverado and i put an HID headlamp conversion (the ones with the ballasts and ignitors and all) on my truck then every now and again my dash lights and guages would go off, and the only thing that would glow would be the two blinker lights, my bright light indicator and the check engine light.. so i would turn off my parking lights and the guages would work, but when i hit the blinker, my guages would bounce and the same lights (blinker, highs & CE light) would flash... now it is always like that, so i took it to the chevrolet dealership that my parents own and they STILL arent too sure what it is:banghead: .... so if anyone could tell me what to tell the mechanic to let him know how to fix it, i would really appriciate it.

that's one of those really really squirelly GM wiring issues.

check for main obvious stuff like crispy wires, melted plastic, etc.

if not that, then you may end up having to go over the whole lighting system to find the bug. which would suck.