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i decided to change my 1978 C3 lights to LED bulbs. After the switch to LED, my turn signals don’t work when I have the headlights on. They work fine when the headlights are off. Can anyone explain the reason or has dealt with this same issue?
what am I missing...
Did you change the flashers to the type used with LEDs?
Yes. But only the one on the fuse box. Now I’ve read where there is 2nd one on the passenger side. I guess
that needs to be changed like the fuse box flasher. Tomorrow’s project!😆👍
If you don't use a quality front marker/turn light (I use the sylvania zevo) that will happen. since the way they are wired with the side marker/turn signals is kind of weird, some of the cheaper 1157 style LED's don't have the internal ground wired so they work right in this style of wiring.
When I put the ones I originally got form superbrite in it would work as you described, when I switched to the sylvania they work properly
(Also of course need the proper flasher as Mel says)
M
Change that flasher first (sometimes you need to run the ground wire for the LED flashers as well) That's something usually you need to prevent hyperflashing anyway
If you still have the issue you describe, look for a decent quality 1157 replacement, I'm sure some of the "Chinese" ones will work but I know the Zevo 1157 will and I didn't want to just keep trying until I found one that worked
M
2025 C2 of the Year ('64-'66) Finalist - Unmodified
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2024 C4 of the Year Finalist - Modified
2023 C2 of the Year Finalist - Unmodified
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Mine is a '74 and I changed all of the exterior lights to LED. I found out after changing the front turn signals to LED switch backs and still had the factory bulbs installed in the front side marker lights when I turned on the headlights the turn signals quit working, once I installed LED bulbs in both front side marker lights the problem went away.
You must use use the electronic flasher with the ground wire. In my car I had to use the the reverse polarity flasher behind the passenger dash pad
Ok. Thanks. I bought my Flasher on Amazon and it did not have the ground wire. I’ll order2 flashers with ground wires and hopefully, that will solve the problem. Your help is much appreciated....👍👍👍
Mechanical flashers- come originally -use a bi-metal that heats and cools- making breaking contact- causing lights to flash.
Also mechanical flashers are rated at current- so if a bulb is burnt out- less current- flashes faster.
LEDs don't pull enough power to heat up the metal and won't work with these types.
Electronic Flashers- use an internal timer that flashes the lights- will not change flash time due to type/amount of bulbs
Must use for LEDs-
There are two type- 2 prong and two prong with a ground wire.
The 2 prong with the ground are not polarity specific- the term "goes both ways"...
The 2 prong without a ground wire IS polarity specific- you must check the polarity.
Originally Posted by Mooser
Mel, Richard, do you have any preference for flasher units?
M
I used these for sequential flashing tail lights...
Forum member Scottewine just posted a thread with the issues he had trying to switch over to LED’s
Search his thread.
He ended up going back to the oem style lights.
It is worth the hassle if you drive at night. compared to a new car c3 corvettes are invisible at night. led bulbs help trucks and crazy uber driver see and avoid crashing into you. Imagine being rear ended while at a stop light. You want to avoid that.
It is worth the hassle if you drive at night. compared to a new car c3 corvettes are invisible at night. led bulbs help trucks and crazy uber driver see and avoid crashing into you. Imagine being rear ended while at a stop light. You want to avoid that.
LED LIGHTS for C3
