Turn Signal Troubleshooting
Thread Starter
Intermediate
Joined: Jan 2019
Posts: 29
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From: Seabrook, NH
Turn Signal Troubleshooting
Hi All;
BLUF - I think I need to replace my turn signal relay.
Problem:
When selecting turn signal right (moving the column lever to indicate right) all systems function as normal. Lights blink on the exterior, and the dash turn signal for right blinks.
When selecting turn signal left (moving the column lever to indicate left) the exterior lights (front, rear, side) do not blink, and the dash turn signal for left stays solid - no blinking.
Third, when putting the lights on; the dash left turn signal is a light / faint green, and the right is not illuminated.
Any thoughts would be helpful. How do i chase this? Or likely root cause? Is it a problem with the column lever?
BLUF - I think I need to replace my turn signal relay.
Problem:
When selecting turn signal right (moving the column lever to indicate right) all systems function as normal. Lights blink on the exterior, and the dash turn signal for right blinks.
When selecting turn signal left (moving the column lever to indicate left) the exterior lights (front, rear, side) do not blink, and the dash turn signal for left stays solid - no blinking.
Third, when putting the lights on; the dash left turn signal is a light / faint green, and the right is not illuminated.
Any thoughts would be helpful. How do i chase this? Or likely root cause? Is it a problem with the column lever?
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Joined: Sep 2013
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From: New Or-leens Loo-z-anna
I just developed the SAME problem. Burned-out bulbs and corroded grounds can cause our problem.
Mine were working perfectly for years before this problem.
There are several Black ground wires coming out of the fender harness and I think there may be a ground wire for each blinker under the dash.
Clean the easy to find grounds first. Also the bulb brass casing and ceter contact can become corroded on some bulbs...probably time for a good cleaning and coating with dielectric grease.
Mine were working perfectly for years before this problem.
There are several Black ground wires coming out of the fender harness and I think there may be a ground wire for each blinker under the dash.
Clean the easy to find grounds first. Also the bulb brass casing and ceter contact can become corroded on some bulbs...probably time for a good cleaning and coating with dielectric grease.
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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I don't believe there is a such thing as a turn signal relay.
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Joined: Apr 2008
Posts: 63
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From: iowa
2025 C3 ('68-'73) of the Year Finalist - Unmodified
I had that problem with my '79. The right front would come on but not blink. Had a short in the turn signal socket. Changed it out and problem solved.
Good luck.
Good luck.
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Joined: Oct 2024
Posts: 80
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From: Michigan
A bad or corroded ground(s) or a corroded socket(s) for the turn/park circuits could force the turn signal power to seek ground through the park light circuit. Power is always looking for ground and will take path of least resistance. In this case, turn signal power is illuminating both filaments of the bulb so that it appears that the turn signal is not blinking. The grease that GM used to fill these sockets to keep moisture out, is now a hard pack cake that long ago lost its ability to repel moisture and makes it hard to remove and replace bulbs. Taking sockets apart to clean out the cake and cleaning both power and ground contacts in the sockets as well as cleaning the frame to circuit grounds are necessary to re-establish lighting circuit integrity. Replacing sockets may also may be necessary in severe cases, but care needs to be taken to seal the spliced wires to prevent future corrosion issues at the splices. That's not to say that other issues can't come into play. The turn signal switch or the flasher can be worn out or aged reducing normal performance, as well as broken or corroded terminals or wires. Do the basic power and ground continuity checks first to isolate the issue(s).
