Turn signal help please!

[namsag]

Driving my '97 LC when I put on R turn signal and got the rapid flashing. I had already made several R turns that day but I figured there went the bulb. Got home and replaced it but made no difference - still the rapid flash.

Tried to read up and investigate to the best of my meager ability. I traced the ground connection near the trailer hitch, cleaned and greased it - in good shape. Turn signal fuse intact. All other turn signal lights work except rear passenger side. Same with hazards. Brake lights and rear side marker light, as well as license plate light on passenger side all OK. Regular bulbs, not LED. My power probe says R rear bulb socket not getting power. Wires look great, all insulation intact, like they have never been buggered with. Wires into socket seem tight, not loose.

What else could it be beside the socket going bad somehow? Am I missing anything else? Is the socket available? Any help/advice appreciated. Thanks, namsag.

 

[izzyandsue]

I had the same exact problem and the solution was to squeeze the socket some (out of round) to ensure contact. I tried new bulbs and no difference. Finally realized it was an intermittent contact on the socket. Just had to make the contact a little tighter.

 

[namsag]

Hey Izzy, thanks for your reply, only one I've gotten. I have read about the squeezing the socket trick, but if the bulb were not lighting due to a loose metal sleeve I'm pretty sure you could still detect power with a circuit tester. My socket has no power. Hoping someone can help me figure out what to try next.

 

[bigredmachine]

could be an issue with the trailer wire harness, when the converter box goes bad it can cause weird issues with teh lighting. try disconnecting the wire harness and see if theres a difference

 

[Darb]

I had the same issue last month and it was the tail lamp pigtail harness. My wires all looked great and in like new condition on my 96 as well. To test all you need to do is remove both tail lamp assemblies from the truck and then follow the wire to the rubber grommet plug into the truck and remove it. Next remove both rear cargo inside panel trim from both sides to gain access to the inside of the quarter panels and pigtail connector. Disconnect both and swap the good side which would be your left to the right side and see if it works correctly. If so then allyou need is a new pigtail connector which are fairly cheap from the dealer.

 

[namsag]

Well I thought I would bump this again to see if anyone has any thoughts.

I followed Darb's excellent suggestion above, swapped the taillight assemblies to see if maybe the taillight pigtail on the passengers side was bad, but alas the turn signal still did not work when I swapped the one I knew was good to the non-working side.

I guess I have a real problem somewhere further up the line. I am about at the end of my ability to find the problem unless someone can offer some new advice.

If no one has any ideas I guess I will have to take it to the one electrical shop in town, I really would rather not bring it to them but I guess I won't have a choice.

Any ideas appreciated. Thanks, namsag.

 

[thedoughboy]

@namsag Do you have a trailer harness? Are you running LED bulbs?

 

[namsag]

I have what I believe is a trailer harness, it's on that (passenger) side, tied to the frame with a ziptie Turn signal bulbs are regular filament bulbs, but I do have LED bulbs in the brake lights and side markers, all of which are working ok.

 

[Mandrake]

I had some major corrosion in the harness that crosses under the truck from the drivers side. Start by checking for power at the turn signal socket with a test light. If it flashes, then you have a bad ground. If it doesnt, you're not getting power. If it doesn't flash, check for continuity to ground from the bulb socket to make sure that's not bad as well. Then start checking the wires. Have fun!

 

[thedoughboy]

When you say rapid flash have you verified that all of the rear lights are illuminating when the need to be? Or, do you get rapid flash and NO right rear illumination?

 

[shocktower]

I have what I believe is a trailer harness, it's on that (passenger) side, tied to the frame with a ziptie Turn signal bulbs are regular filament bulbs, but I do have LED bulbs in the brake lights and side markers, all of which are working ok.

The brake lights are your blinkers that is your problem

 

[namsag]

@doughboy: yes, all other lights, brakes, side markers. both front turn signals, driver's rear turn signals all operating normally.

 

[thedoughboy]

So, the right rear turn signal does not illuminate? I am sorry but I thought you stated passenger side was not working...

"All other turn signal lights work except rear passenger side."

Edit: I think I answered my own question.

 

[thedoughboy]

I guess I should add. IF only one side is NOT illuminating and you are getting rapid flash you have a bad bulb or (most likely) a grounding issue. It seems that grounding issues with trailer harnesses are somewhat common. In order to fix this you'll need a multi-meter. Multi-meters allow you to check ground integrity and + voltage.

I would start at where your trailer harness taps into your rear lights.

 

[namsag]

Correct. Everything working but passenger side rear turn signal.

 

[thedoughboy]

Youtube has some good videos on using a multi-meter on vehicles. If you don't want to do that you'll need to take it to a shop. However, learning how to use a multi-meter is pretty easy and very useful.

Let me know if you have any questions.

 

[namsag]

Thanks for the advice. Unfortunately I will have to work all weekend, will be Monday before have a chance to mess with it again.

 

[incogrhino]

All else fails...ya can tap in to the front and run power to the back light. Ghetto yes,does it work.....yep.

 

[namsag]

That's what I'm afraid the local electrical shop will do!

 

[davidp14]

Was this ever solved??

I have the exact same problem. I replaced the bulb, and fuse.
Can't be flasher is 3 other signals work, right?