Problem with Left Turn Signal/DRL
Thread Starter
Teching In
Joined: Dec 2009
Posts: 6
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From: Austin,TX
Problem with Left Turn Signal/DRL My driver side turn signal/DRL will not light at all. I purchased new lights because my passenger side was cracked and kept blowing the bulb when water got in. I replaced the passenger side light housing, bulb, and socket. It works fine now. I ordered a light for the driver side also and replaced it. I have never had a problem with the driver side light. When I opened it I found out someone had previously replaced the socket on the driver side. It was not leaking but the lens was cracking and the socket was pretty toasty. Mind you, the driver side was working fine. I replaced the socket and now it does not work at all. I tried three different bulbs, all which work on the passenger side. I measured the voltages in the socket, I get ~12V on the blue/outer tab, but the brown/center tab is not getting any voltage. I probed the harness side of the splice to the socket and there is good continuity. I looked at the wiring diagram and don't see anything like a fuse that would affect only that socket. Any ideas?
Thanks in advance.
By the way, My wife jinxed it because she said "why replace that lens when the light is working".
Thanks in advance.
By the way, My wife jinxed it because she said "why replace that lens when the light is working".
Joined: Nov 2003
Posts: 11,328
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
There are three wires to each front socket. The blue wire is power for the DRLs and turn signals - the bright filament in the bulb. The brown wire is power for the parking lights - the dim filament in the bulb. The black wire is ground.
You should have power on the blue wire when the ignition is on, the headlights are off and the parking brake is disengaged. It should change from steady power to flashing power when the ignition is on and that side turn signal is activated.
You should have power on the brown wire when the headlights are on. You may or may not have power there when the parking lights are on - some models continue to use the bright/DRL filament (blue wire) when the parking lights are on without the headlights.
You should have ground on the black wire at all times - the ground is a bolt on the top of the radiator support on each side.
I suspect that if the light doesn't work for either the bright or dim filaments then you have a bad connection on the ground (black) wire. If one works but the other doesn't (i.e. bright works but dim doesn't or vice versa) then it's the power feed for that filament - the socket itself, the connection to the factory harness, or something in the factory wiring.
You should have power on the blue wire when the ignition is on, the headlights are off and the parking brake is disengaged. It should change from steady power to flashing power when the ignition is on and that side turn signal is activated.
You should have power on the brown wire when the headlights are on. You may or may not have power there when the parking lights are on - some models continue to use the bright/DRL filament (blue wire) when the parking lights are on without the headlights.
You should have ground on the black wire at all times - the ground is a bolt on the top of the radiator support on each side.
I suspect that if the light doesn't work for either the bright or dim filaments then you have a bad connection on the ground (black) wire. If one works but the other doesn't (i.e. bright works but dim doesn't or vice versa) then it's the power feed for that filament - the socket itself, the connection to the factory harness, or something in the factory wiring.
Thread Starter
Teching In
Joined: Dec 2009
Posts: 6
Likes: 0
From: Austin,TX
There are three wires to each front socket. The blue wire is power for the DRLs and turn signals - the bright filament in the bulb. The brown wire is power for the parking lights - the dim filament in the bulb. The black wire is ground.
You should have power on the blue wire when the ignition is on, the headlights are off and the parking brake is disengaged. It should change from steady power to flashing power when the ignition is on and that side turn signal is activated.
You should have power on the brown wire when the headlights are on. You may or may not have power there when the parking lights are on - some models continue to use the bright/DRL filament (blue wire) when the parking lights are on without the headlights.
You should have ground on the black wire at all times - the ground is a bolt on the top of the radiator support on each side.
I suspect that if the light doesn't work for either the bright or dim filaments then you have a bad connection on the ground (black) wire. If one works but the other doesn't (i.e. bright works but dim doesn't or vice versa) then it's the power feed for that filament - the socket itself, the connection to the factory harness, or something in the factory wiring.
You should have power on the blue wire when the ignition is on, the headlights are off and the parking brake is disengaged. It should change from steady power to flashing power when the ignition is on and that side turn signal is activated.
You should have power on the brown wire when the headlights are on. You may or may not have power there when the parking lights are on - some models continue to use the bright/DRL filament (blue wire) when the parking lights are on without the headlights.
You should have ground on the black wire at all times - the ground is a bolt on the top of the radiator support on each side.
I suspect that if the light doesn't work for either the bright or dim filaments then you have a bad connection on the ground (black) wire. If one works but the other doesn't (i.e. bright works but dim doesn't or vice versa) then it's the power feed for that filament - the socket itself, the connection to the factory harness, or something in the factory wiring.
Thread Starter
Teching In
Joined: Dec 2009
Posts: 6
Likes: 0
From: Austin,TX
I probed all the socket tabs:
Ground is good to the body ground at the radiator.
Blue wire is 12V and pulsing when turn signal is on.
Brown wire is 12V when the head lights are on.
If I push the light bulb in really hard, I can get it to light but not flash. I am going to get another socket and try it.
Ground is good to the body ground at the radiator.
Blue wire is 12V and pulsing when turn signal is on.
Brown wire is 12V when the head lights are on.
If I push the light bulb in really hard, I can get it to light but not flash. I am going to get another socket and try it.
Joined: Nov 2003
Posts: 11,328
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
The socket sounds like it might be the culprit. One other thing I've found is that some sockets aren't tight enough to make contact with the wire contacts on 3157 style bulbs. Often you can fix that by carefully bending the bulb's contact wires outward using a pair of needle-nose pliers so that they press against the socket contacts better.
