Occasionally my left turn signal indicator lights up

[rsh4364]

About once a week my left turn light indicator lights up,voltmeter reads normal, bulbs all good. Bad grounds maybe? I drive about 2 hrs. To Columbus, then 10 miles each day til Friday,then 2 hrs back home.Only seems to happen on the long trips.When it does happen I turn on left blinker for a few seconds and it stops.

 

[cpf240]

Are the running / headlights on when this happens? I could see a bad ground maybe causing this if the other lights are on. Otherwise, my guess would be a failing turn signal switch.

 

[cucvrus]

IMHO I think you have a bad filament in one of the bulbs front or back on that side. That is why the turn indicator is lighting to tell you that. Check it out and report back. Have a great day.

 

[the skull]

^^^ This has been my experience with most of
my GM stuff, you know something is up when the
turn indicator lights up

 

[wcuhillbilly]

IMHO I think you have a bad filament in one of the bulbs front or back on that side. That is why the turn indicator is lighting to tell you that. Check it out and report back. Have a great day.

^^^ This has been my experience with most of
my GM stuff, you know something is up when the
turn indicator lights up

The GM system by design illuminates the turn signal on the side of the bad ground or short when a voltage irregularity is detected in the stop/turn lamps. Ive had this trouble for years and the only diagnosis method I have is to turn the park lights on and walk around checking for dead light, then turn on hazards and repeat, then turn off hazards and turn on turn sigs repeating walk around each time... Mine was narrowed down to the left turn light in the grill below the headlight, ther is the main socket with two wires coming into it from the rear, and then there is a small brown(IIRC) wire on the side of the socket. This brown wire has a special end on it that contacts the side of the bulb base via a brass ribbon. I have fought with this ribbon for years to keep it contacting. Visual inspection will say nothing is wrong but a function check will reveal a bad connection.
Carquest and Napa sell replacement sockets with short lead of wire for that socket, I have two but dont like abunch of but connectors in my wiring harness, so I continue to clean this problem spot about once every year or so, especially after moist conditions.
As much rough and ranch roads as I run, Im surprised that I dont have more frequent electrical problems, but such is the quest of elemination of the electrical tom foolery from my rig...

 

[Hasdrubal]

Mine did that occasionally also, turned out to be a broken ground tab on the front turn signal/marker light. Didn't have another socket at hand, so cut and stripped a small piece of wiring. Twisted it so it wont fray apart, bent it in half, inserted one end into the side of socket body where broken ground tab is located. The other end of wire now contacts the side of bulb, completing the circuit. Fixed.

 

[rsh4364]

Drove it this am in 2 degree weather,when I got to shop left front bulb not working.So now I have my answer.Strange how it would go bad slowly.Then I drove to east side to work for a few hrs.Drove back to my motel and bulb started working again,at least now I know where to start.Thanks for the input guys.

 

[cucvrus]

You need the $3.99 Autozone light socket modification. That small tin ground contact is probably broken off in the socket. Or do what Hasdrubal says to do. Fixed. That was easy.