The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Strange turn signal issue on 72 C-10

72bowtiestepper · 12-02-2020, 11:21 AM

Wrapping up the multi-year restoration build on my 72 stepside and have run into a problem with the turn signals. With headlights OFF, all signals front & rear including front marker lights & dash indicators work great.

With headlights ON all signals are REVERSED....Switch lever down for a left turn..the right signals front & rear are activated. Switch lever up for a right turn....the left signals front & rear are activated. The dash indicators are opposite also. The brake lights are fine and work with headlights off or on.

I searched in old forums about issues with turn signals & found many people have had grounding issues, so I ran a dedicated ground to each signal housing front & rear.....No change. With headlights on signals are still reversed left to right & right to left. Any ideas what could be causing this ??

12-02-2020, 11:21 AM	#1
72bowtiestepper Registered User Join Date: Feb 2013 Location: Northwest NJ Posts: 684	Strange turn signal issue on 72 C-10 Wrapping up the multi-year restoration build on my 72 stepside and have run into a problem with the turn signals. With headlights OFF, all signals front & rear including front marker lights & dash indicators work great. With headlights ON all signals are REVERSED....Switch lever down for a left turn..the right signals front & rear are activated. Switch lever up for a right turn....the left signals front & rear are activated. The dash indicators are opposite also. The brake lights are fine and work with headlights off or on. I searched in old forums about issues with turn signals & found many people have had grounding issues, so I ran a dedicated ground to each signal housing front & rear.....No change. With headlights on signals are still reversed left to right & right to left. Any ideas what could be causing this ??