Electrical problem

[Tully]

I have a problem with my 71 GMC K 2500. All the lights work fine inside and outside until I turn the dash lights on. What happens is with the dash lights on the turn signal indicator lights and the high beam light come on dim and quit working properly. When I turn the light switch till the dash lights go off every thing works fine again. All I can think of in replace the light switch then if that doesn't work I would suspect the circut on the back of the benzel. I am hoping someone else has had this problem and can offer some insight.

[franko72]

I had a similar problem with my 69 nova years ago. I changed the light switch and still had the same problem.I unplugged my dimmer switch on the floor board and tried it.lights worked fine. Found a short in the dimmer switch .Changed my dimmer switch and it fixed my problem. Try unplugging your dimmer switch. I t would be a long shot, but it wouldnt take long to check.

[franko72]

also check all your your 1157 bulbs .you could change them out one at a time with a new bulb and check as you went along. I have had bulbs short out and mess the lighting circuit up before.

[Tully]

Thanks Franko 72, I will try checking both those tomorrow.