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Hello all, I recently acquired a 71 Cutlass and I'm trying to troubleshoot my turn signal issue. Neither of the turn signals are working. I checked the fuse that controls the turn signals and b-up lights and it's good and registers power when probed with the key in the on position. I replaced the the flasher that sits behind the dash (previous owner left it dangling below the dash) and nothing happened. After reading several threads someone suggested to probe the wires at the turn signal switch connector. The probe blinked when I tested the brown wire for the hazards, but did not react when I probed the dark blue and light blue wires for the signals. I ordered a turn signal switch and plugged it in without installing it into the steering column to see if the switch was bad. The turn signals still didn't flash. Let me add, I don't have reverse lights either. Next step is the neutral safety switch (NSS). According to the attached wiring diagram it looks like the green/ white wire that connects to the fuse panel runs to the turn signal flasher and the NSS. Iknow the NSS affects the b-up lights, but I didn't think it would ager the turn signals.
I have two questions that I can't figure out from the diagram.
1. What do the green and purple wires from the flasher attach to behind the dash? Does it plug into something else?
2. Shouldn't the green wire attached to the flasher register hot if probed with the key on? I didn't get anything when I unplugged the flasher and tested the wires.
I know the hazards are on their own circuit. All bulbs flash with the hazards on, so I know the bulbs are good.
I'm at a loss right now. Any insight or suggestions worth this matter is greatly appreciated.
Just a couple of quick comments that I do when trouble shooting.
Easy checks first like you did with the bulbs (but unlikely all would be out)
Make sure the ground path is good; odd things go on with poor ground connections
I usually start from the power source (ie the battery) and check it along the way to the trouble area. So trace back how your turn signals get power from the battery and check the items along that path.
Since all the lamps work with the 4 ways, I'd consider the ground path good. Make sure you have 12v to the signal stat green wire. The purple will blink 12v if the signal switch is in the left or right position. Check the connector for the column and look for pushed pins.
Thank you both for the information. I believe obtaining the 12v source is my issue. According to the wire diagram, it looks like the green/white wire connects to the fuse panel, NSS plug, and flasher. I want to make sure I'm thinking correctly. Shouldn't I see a green/white wire coming from the fuse panel and branch off at some point to feed the NSS and flasher?
For testing purposes, if I connect a different 12v source to the flasher will that allow for the turn signals to operate? I will double check again, but I don't believe I'm getting power to the green/white wire.
I have two questions that I can't figure out from the diagram.
1. What do the green and purple wires from the flasher attach to behind the dash? Does it plug into something else?
No, the two wires are part of the dash harness.
2. Shouldn't the green wire attached to the flasher register hot if probed with the key on? I didn't get anything when I unplugged the flasher and tested the wires.
Yes, that wire should be hot with the key on. It also feeds the backup lights and the TCS solenoid. If you don't get power on that terminal in the flasher connector, that's your problem Trace it to find where the break is. My money would be on the splice.
Thanks again for your responses. I checked the stat green wire again and there was no power going to the wire. I unplugged the flasher and ran a wire directly to it from the signal fuse and and attached a wire from other flasher prong to the purple wire of the flasher plug. Turn signals worked just fine. As Joe Padavano suggested, it's time to do some wire tracing. Let the fun begin.
It's easy enough to tell if the backup lights work or not.
He said the back up lights do not work in post #1.
Originally Posted by kan4club
Thanks again for your responses. I checked the stat green wire again and there was no power going to the wire. I unplugged the flasher and ran a wire directly to it from the signal fuse and and attached a wire from other flasher prong to the purple wire of the flasher plug. Turn signals worked just fine. As Joe Padavano suggested, it's time to do some wire tracing. Let the fun begin.
I bet it's the fuse as the back up lights are powered from the same source.
Battery disconnected, pull the TS/BU fuse. Then test the fuse for continuity using self powered test light.
If it's good, use the self powered test light to check circuit continuity from load side of the fuse clip to the backup lamp switch and then to the turn signal switch. If you're lucky the circuit is intact; if not, get out the wiring diagram and electrical repair tools and have fun.
Won't hurt to clean those fuse holder clips either. Fiberglass eraser or fine sandpaper should do it.
February 13th, 2022, 08:06 AM
