When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have switched over to led lights on the exterior. turn signals do not blink. i installed the led blinker relays provided by superbright led but no blink, solid light. then purchased an after market led relay, no blink, solid light. i reinstalled one regular bulb on each side using a regular relay and they blink. I am looking for some advice on what led relay people have had success, or whatever other advice you have. regards Atlanta
It's been years since I did the LED conversion on my 71 but I remember the front side marker is the problem. It's wired to come on with the running lights and then flash with the blinker. The stock wiring of this relies on the bulbs passing current from one bulb to the other which LEDs won't do. I had to move one wire from the side marker so that it was wired in parallel to the front blinker. The way mine works now is the side marker no longer lights up with the running lights and then flashes together with the front blinker. AFAIK this setup is legal. there's no requirement to have a front marker light.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
my 68 acts the exact same way...I just left it like that. YOu may have to by resistors and solder them in line at the lights. THe flasher relay senses the current draw which is about zero with the LEDs so you have to add that resistor for the flasher to see it. I added the LED flasher and it dosent work either
You will need this flasher or an equivalent other brand. The black wire connects to any ground.
You will have to check the flasher connector on the wiring harness. You may have to reverse the terminals. Electronic flashers are polarity sensitive. That takes all of 5 minutes. There are polarity reversing adapters if you don't want to do that. If you swap terminals and want to go back to a thermal flasher, you can leave them swapped.
I happen to like this one because the switching is done by a mechanical relay so it sounds like a real flasher instead of the nerve wracking sound modern electronics make.
What Avispa said, the electronic flasher relays are polarity sensitive, temporarily switch the leads on your flasher relay with alligator clip jumper leads to test.
Or just look at the connector. Brown goes to X terminal on the e flasher, purple to the L terminal. 68s might have a different wire color setup. The terminal that gets 12 v with the key in ON or ACC goes to X.
I've been on a 30 year light bulb mission after I almost rear ended a 40 Chevy coupe. His tail light was almost invisible. Four 1157s in the butt end of a C3 aren't a whole lot better with all the cars on the road these days having huge, bright LED backside lamps. Save the 1157s for the NCRS when you get your car judged.
Is it a three wire relay? Try leaving the ground lead, and swapping the other leads (you can make two short jumpers, or use alligator clips to test).
I used this United Pacific flasher. If you order the one with the swappable base, it's easy to switch the leads. I think I used the swap in one of the two positions of my 79, perhaps just the turn signals, but not the hazards. At any rate, it did NOT work without swapping the base leads. I don't know if this fits your 68, though.
Here's my writeup on LED lessons learned in my 80. I don't think you 68 has front marker lights, so you might be spared that agony.
My 1988 Pontiac FIERO has a similar problem. I use the non polarized LEDs and it make the problem even worse. I eventually just put the incandescent bulbs back in the front turn signal / parking lights. It didn’t make sense to start rewiring the side markers. On my 73 Corvette, the parking light LEDs caused the green indicator lights on the dash to come on when the headlights were turned on. My reason for using LEDs in the exterior lights is to reduce heat build up. The third break light on my FIERO was an OEM halogen bulb in a plastic case inside the car. What was Pontiac thinking. Needless to say the lens was melted pretty bad, especially since the car has a manual transmission. I found a nice LED light strip and then had to buy a new third brake light assembly, thanks Pontiac.
tried the union pacific relay and no joy, tried several others with same problem. used the polarity reverse plug that came with the union pacific on another relay and Bam... I am in business.. thanks for the responses. Atlanta
tried the union pacific relay and no joy, tried several others with same problem. used the polarity reverse plug that came with the union pacific on another relay and Bam... I am in business.. thanks for the responses. Atlanta
Thanks for updating with a resolution! I'm glad it worked out, however it worked out.
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
LED Conversion
Originally Posted by Bikespace
Is it a three wire relay? Try leaving the ground lead, and swapping the other leads (you can make two short jumpers, or use alligator clips to test).
I used this United Pacific flasher. If you order the one with the swappable base, it's easy to switch the leads. I think I used the swap in one of the two positions of my 79, perhaps just the turn signals, but not the hazards. At any rate, it did NOT work without swapping the base leads. I don't know if this fits your 68, though.
Here's my writeup on LED lessons learned in my 80. I don't think you 68 has front marker lights, so you might be spared that agony.
Finally got around to converting my 72 C3 to LED. Same issue with blinkers. By reversing the leads with a pair of jumpers on the blinker, solved the problem. Big thanks to Bikespace for this infor.
1968 LED conversion blinker problem
