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Left front turn signal dosent light up

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Old 06-27-2012, 08:54 PM
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Smile Left front turn signal dosent light up

My left front turn signal dosent turn on. I already switched the bulb and socket, I tested the wire that lights up the turn signal but had no current and the rear light turns on and stays solid the drl's do work. My car is a 98 Trans Am. What could be wrong?

Thanks in advance for any input......
Jay
Old 06-28-2012, 06:28 AM
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bad flasher
Old 06-28-2012, 07:43 AM
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^ That is possible but very unlikely. The same flasher runs both sides. There have been some cases where one side would flash but not the other because of a marginal (failing) flasher with different resistance in the left and right circuits. But the bulb would still turn on even though it didn't flash.

In this case he is getting no power to the blue wire at the left front socket with turn signals yet the DRLs still work. So we know the wiring and socket are intact and the bulb isn't burned out (DRLs use same wiring and bulb filament). It could be the turn signal switch except that the rear light still comes on. I suspect a problem with the DRL module although that is very unusual. Test it by checking for flashing power input on the light blue with white wire at the DRL module then checking for output on the light blue wire. If you have input but no output then the DRL module is the problem.
Old 06-28-2012, 12:17 PM
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^^ Correct. My bad. (I missed the "no" before "current" in the original post.)
Old 06-28-2012, 01:46 PM
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Originally Posted by WhiteBird00
^ That is possible but very unlikely. The same flasher runs both sides. There have been some cases where one side would flash but not the other because of a marginal (failing) flasher with different resistance in the left and right circuits. But the bulb would still turn on even though it didn't flash.

In this case he is getting no power to the blue wire at the left front socket with turn signals yet the DRLs still work. So we know the wiring and socket are intact and the bulb isn't burned out (DRLs use same wiring and bulb filament). It could be the turn signal switch except that the rear light still comes on. I suspect a problem with the DRL module although that is very unusual. Test it by checking for flashing power input on the light blue with white wire at the DRL module then checking for output on the light blue wire. If you have input but no output then the DRL module is the problem.
THANKS for the reply.... Is the drl module located behind my stereo?
Old 06-28-2012, 02:09 PM
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I have the same problem and the DRL is my last problem. Mine started with all ABS TCS and Brake lights on and I have damn near rewired the whole car fixing the problems... but have not find the last problem. Min seems to be a weak ground because it will dimmly ( if thats a word) come on like it wants to but it want. Where is the wire harness for the Blue,Brown and Black wires run? So i can jump the blue and see if its the problem.
Old 06-28-2012, 02:46 PM
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I already tested the light blue with white wire for current and their is current when i put the turn signal i understand this is the input. I also tested the dark blue with white but their was no current this is the output.DO I HAVE A BAD DRL MODULE?
Old 06-28-2012, 02:50 PM
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Originally Posted by old93camaro
I have the same problem and the DRL is my last problem. Mine started with all ABS TCS and Brake lights on and I have damn near rewired the whole car fixing the problems... but have not find the last problem. Min seems to be a weak ground because it will dimmly ( if thats a word) come on like it wants to but it want. Where is the wire harness for the Blue,Brown and Black wires run? So i can jump the blue and see if its the problem.

Those wires go to the back of your stereo its a black box just un clip itvand you can pull it ou enough to work on it
Old 06-28-2012, 03:45 PM
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Originally Posted by LS1TA_956
I already tested the light blue with white wire for current and their is current when i put the turn signal i understand this is the input. I also tested the dark blue with white but their was no current this is the output.DO I HAVE A BAD DRL MODULE?
No, there are four blue wires in the DRL module. Two are light blue and two are dark blue. The two light blue are the left side (white stripe is input, plain is output). Similarly, the two dark blue are right side (white stripe is input, plain is output).

So after testing the light blue with white left side input wire, you should then test the plain light blue wire for left side output.
Old 06-28-2012, 03:55 PM
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Originally Posted by old93camaro
I have the same problem and the DRL is my last problem. Mine started with all ABS TCS and Brake lights on and I have damn near rewired the whole car fixing the problems... but have not find the last problem. Min seems to be a weak ground because it will dimmly ( if thats a word) come on like it wants to but it want. Where is the wire harness for the Blue,Brown and Black wires run? So i can jump the blue and see if its the problem.
The blue wires run to the DRL module behind the stereo for DRL and turn signal. The brown wires run to the headlight switch for the parking lights. The black wires run to the radiator support brackets for ground.

It is quite possible that you have a ground problem. With dual filament lamps like these, the current will back-flow through the other filament when there is no good ground, causing the light to illuminate dimly.
Old 06-30-2012, 10:04 AM
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will check it out today, thanks for the help



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