headlights on no tach/boost gauge or turn signals?

[l3lue]

with my headlights OFF my turn signals and that work fine...but with them on, my turn signals stay on and dont click and my tach turns off as well as my boost gauge and i think my brake lights also might not work iwth teh lights on..what is this all about? loose ground or something?? help me out thanks

[kenmosher]

Bad headlight switch would be my first guess ... also check the panel light dimmer wheel.

[mikes87gn]

I have almost the same problem - no instrument (illumination) lights, boost/tach light, radio, shifter light, but turn signals work. I bought a used headlight switch w/dimmer but haven't tried it yet (GN in another state).

I changed headlights to Silver Star and installed a used radio w/EQ - the illumination lights stopped working later...

[Hyser]

Originally Posted by mikes87gn

I have almost the same problem - no instrument (illumination) lights, boost/tach light, radio, shifter light, but turn signals work. I bought a used headlight switch w/dimmer but haven't tried it yet (GN in another state).

I changed headlights to Silver Star and installed a used radio w/EQ - the illumination lights stopped working later...

Same issue; My fix: On my 87GN the previous owner attempted an install of an aftermarket alarm system. I found one of the rigid wires located in trunk near back corner to have a weak connection. Checked all bulbs including dash, replaced a couple, check all fuses. Now works fine! Good luck!