Hey all, got a question for the wizards out there on my 81...

i changed the exterior bulbs to LED bulbs (i like the look so no hate) and everything works wonderfully except the passenger side turn signal.

When no marker lights are on, it flashes normally when turning right and the hazards work fine. Put the parking lights on and it only goes into the bright mode but doesn't flash.

The dash indicator is blinking normally but the front and rear bulbs don't flash.

hazards don't flash either with lights on

The drivers side works perfectly with no lights and lights on.

Whats been done:

- changed both front turn signal sockets soldered and heat shrunk tubing the connection.
- checked and wiring is done the same on both sockets.
- swapped bulbs from driver and passenger side knowing 1 bulb is good - same outcome
- checked with a test light to make sure sockets weren't the issue. Both sockets/wiring is acting the same and its showing that its “flashing” on the test light. Marker light and flasher are the same on both sockets.
- put a normal filament bulb in pass side socket and it works normally
- installed LED compatible electronic flasher for turn signals

Ive heard that the hazards are on a separate flasher and that relay has not been changed to an electronic flasher. Where is that relay? Is it the round one similar to the turn signal on high up on the firewall fuse panel??

what would cause that one side to not work???

thanks in advance

 

Neither your post or your profile give a clue as to what year the car is.
On my 69 there are two flashers.
One in the fuse box and the second behind the passenger side dash pad and can be accessed by looking under the dash.

 

My apologies - its an 81

 

If you haven't already purchased the AIM, Assembly Instruction Manual and the factory service manual for you 81. Not the Haynes or chiltons. The AIM will help determine where some of the parts a located. Sorry no help on the LED question.

 

I changed the bulbs on my 77 to LED. Had to change both flasher modules if I remember correctly. Be sure to get a polarity reversing module with ground wire.

As far as the C3 goes...every post I looked at, someone had a different problem when changing to LEDs. I had to do a bit of trial and error with all of my lights to get everything correct...including using a couple regular bulbs.

I ended up with xenon headlights, incandescent front blinkers and LED everywhere else...including the interior and instrument cluster.

like I said, it got down to trial and error with different incandescent/LED combinations to make everything work.

 

thanks John, I am beginning to think that for some reason the Hazard flasher is my issue for the pass side light...

i just dont understand why they work when no parking lights are on, but freak out when the parking lights ARE on.

🤷‍♂️

 

usually a corroded ground wire to the frame causes weird signal issues. The LED light may be compounding the problem since the passenger side signal works correctly with the higher amperage filament bulb.
Or...a marker light wire is shorting against a turn signal wire.

 

i thought that too and i looked at the new wiring and the splices to make sure they were good and at least they looked good - i didn”t check the entire wire

thanks for the info - ill have to check the grounds when im under it again.

 

My rear tail lights were doing weird things...the ground to the frame looked O.K. but there was rust under it.
I would rather rebuild a differential than deal with a wiring problem

 

AMEN! I hate electrical gremlins....


edit - checked the grounds to either side of the radiator and the screws are used to secure SOMETHING in the wheel well/fender area. Wires look good but want to know what its connected to before randomly removing things

 

I'll only put this out as some info, perhaps nothing to do with your situation and I haven't looked at the 81 turn signal wiring method

GM used a strange method of dealing with the turn signals with and without the park lights on, The power is sort of grounded when the lights are on and the LED doesn't let it try to go backwards as the regular bulb does. The "good" bulbs seem to handle it fine while some of the cheaper ones don't have the circuitry to allow it to work the way GM intended (which wasn't the way LED are supposed to work)

If it works with regular 1157 bulbs in the front and LED on the sides, then this could be related to your issue

M

 

the last one is what mine is doing. I didnt buy cheap bulbs by any means and have bought from them before with no issues.

thats more info right there than ive found in days of internet searching

 

this is exactly what the passenger side is doing (last one) Drivers side works fine and as intended

bulbs are not cheapo bulbs by anymeans and have purchased before for other vehicles without issue

sounds more and more like a ground issue???

 

Pop the regular bulb back in the front and see (the one side that isn't working)
Since it's just one side I would suspect a ground issue but if the bulbs aren't working properly 100% it will make any other fault show up
M

 

I already did that while troubleshooting and went so far to use a test light on the socket on both sides (lights on & off) to make sure it was getting the signal to flash and to make sure things were wired correctly and identical - which they were

old bulb works fine, and flashes normally

 

I think what Mooser suggested is the most likely solution. The way the lights are installed on these cars requires current to flow in both directions at the front turn signal. See if the standard bulb fixes the problem. If you really like the look of LEDs (I have them in my cars, everywhere except the front turn signal), @Richard454 posted a quick fix solution module that addresses this problem. I'll add the link if I can find it.

The other possibilities:
You likely already did this, but just to confirm, you need a 3-wire LED flasher in both positions, turn signal and hazards. The unit that comes with the swappable base makes debugging easier.

Internal disconnect in one of your sockets (never trust old parts, and never trust new parts). This connector had failed, but not completely, so my turn signals would sometimes work.

 

Here you go. This thread might help:

https://www.corvetteforum.com/forums...nightmare.html

And this is the part that @Richard454 suggested in another thread:

https://chromeglow.com/products/blin...ignal-circuits

 

Bikespace - ok, i have a 3 wire in the turns but not the hazard. Mostly because the hazards are working fine. Ill have to order another one though to take the relays out of it and any potential bugs.

Because 1 side works and the other doesn't just messes with my mind when it comes to troubleshooting.

also, i will take a look at the connectors inside the socket and see if i can't make the connection better and see if it helps.

The sockets are from the same place, wired the same and the bulbs are from the same place and when the leds are swapped (funky socket to known good socket) that bulb works. As you guys throw info at me, it is sounding more and more like a ground/wiring issue on that side. Just gunna take me a little to find it all.

 

To ADD To the Confusion. I installed high quality NON Polarized LEDs in the Instrument/Gauge Cluster on my 73. Really turn out great. Next I changed out the front Turn Signal and Side Marker Lights, along with two electronic flashers (with ground wire). Problem occurred when I turned on the Headlights, Both Green TURN Signal Indicator Lights Came on. After spending way too much time, I reinstalled the old Filament Bulbs and moved onto another problem. Had a similar problem with a Pontiac, because the Side Markers are run through the front turn signals, so that they are illuminated when the turn Signal Lights are not. Had to go back with filament bulbs in the turn signals

 

I had the same problem with my '75, no LEDS in the dash but in all 4 turn signals.
I removed the front LEDS and all is well.
I'm more worried about being rear ended than if my front turn signals are brighter.
BTW this is were I purchased the LEDS.
https://secure.cougarpartscatalog.co...sionthemeid=26
After trying several LEDS in my replica Lucas tail light on my Triumph Bonneville, I found these, they are high quality and very bright, not cheap tho!