Hi, Got my Suburban back from the body shop from having it painted, They replaced the rear taillight and front turn signal assemblies. Been stored for the last 3 months. bringing it home noticed the left turn signal blinks as normal but the right turn signal flashes very fast. There is no flashing from it. I pulled the front assembly and checked the bulbs and . they are good. I removed the right rear taillight assembly and swapped it with my old one they left me. No change. Could they have possibly left a ground wire off.

 

Update, I replaced the turn signal flasher and the the 2 front 1157A bulbs. Same issue.The volt meter on DC flashes OL super quickly when I connect it to brown wire ( ground ) and light green tab that activates the turn signal bulb. It flashes at same as the dash turn signal lamp.

 

Sometimes after a paint job, the grounding connection is interrupted by the new paint. Test by temporarily running a separate ground wire.

 

The OL on your meter is the auto range feature trying to switch your meter to the correct voltage range. Find the manual range option on your meter and set it for 20V (depends on the brand)
The brown wire is NOT the ground, the Black wire is ground. Light green (schematic calls it light blue) is the turn signal, the brown is the park lamp.
A sign that you have a bad ground is to look closely at the filaments of the bulb while it's flashing, with the lights OFF. If both filaments are flashing, you might have a missing ground.

 

O.K. Yes the flutter is auto switching. Going to use Simpson meter as it is analog. And my thought was a ground too. Possibly they tampered with my trailer hitch wiring. Going to check that out after it rains here. And will look at it after dark. When I pulled the 2 front bulbs for the parking / turn assembly on the right the little side marker light went back to regular flashing. I swapped out the old right rear tail light assembly thinking possibly it was a bad unit but acted the same. Will post when I get out there. Thanks.

 

Hi, stopped raining. Went out and yes mis quoted wires. Brown marker light green turn signal wire. Black wire shows 22,5 ohms to bumper ground. So I took a wire and connected it to the battery ground and ran it to back of the truck to the black wire on the harness. Bingo lights work! The body shop must have disturbed it. Going to chase the black wire back and repair it once the ground dries up and go underneath truck. Thank you for the help on this. Appreciate the input. She has 135,000 miles on her from Texas. Body is beautiful but had scratches on her and 25 years of sun beating on her. She looks showroom new now.