Installed LEDs in turn signals - no flash (even with LED flasher module)

[jawn101]

Just as the title says: perfectly working 4-ways/turn signals with incandescent bulbs installed. The flasher relay is an LED compatible one. Replaced both rear bulbs, everything was fine. Replaced one of the front ones (yes, an 1157 bulb, installed in the right direction) and the flash turned to the "fast blink" which indicates a bulb out. I chalked this up to a differential in draw between the new LED in front and the one remaining incandescent bulb. Replaced the 4th and final bulb and the flashers just don't blink at all now. The dash indicators flash once, then nothing.

Any ideas?

[jawn101]

Oh and I forgot to mention - yes, the "low" setting comes on the front LEDs with the running lights/headlights engaged.

[Bitsyncmaster]

My guess is your new flasher is bad. Stick the old one back in and verify you get the fast flash if any.

[jawn101]

Hmm. Been running this one for ages. Don't have the old one anymore as it completely deteriorated. Guess I could go grab a new one at o'reilly - but it works fine when I put the old bulbs back in?

[DavidProehl]

Wild (and maybe wrong) theory: Is it possible your new LEDs draw less power than your old ones and your older flasher relay assumes they are older, higher draw LEDs?

No idea how the LED relays work, but it just seems to me like the problem is with your relay. You have proven the circuit is good because it works with the old bulbs, you've confirmed the new bulbs light up individually, so the only thing untested is your relay.

[jawn101]

More weirdness. I just noticed that the fast flash is including the side marker lights. Those don't usually flash when the turn signal is on, do they? I can't remember now. The problem seems to be in the RH side somewhere.

[jawn101]

Ok, reading a little more online I found http://www.dmcnews.com/Techsection/markerflash.html - a mod which is meant to make your side markers flash just as mine seem to be.

This tells me two things:

#1, this should not be happening because I have not done this mod.
#2 it is possible that, given the fact that this mod is all about grounding the G/R wire in the front DI, these new LEDs are somehow internally shorted (or their terminals on the base are oversized maybe?) such that the sockets are grounding out and messing up the circuit.

Does that make sense? Am I chasing a red herring? I did get into the sockets with a bit of fine sandpaper and electrical terminal cleaner just now to make sure everything is nice and clean and tight.

[Josh]

if you have done that mod the lights will behave as they are. An LED is a diode, so this configuration will not work with them as the current is flowing the wrong way for the diode to energize.

Perhaps it would be a good idea to confirm the wiring is not already modified by a PO so you can rule another thing out.

[May81DeLorean]

I also started with perfectly working 4-ways/turn signals with incandescent bulbs installed. Based on the advice of other owners, I installed a Novita EP35 LED compatible electronic flasher, and Sylvania ZEVO amber LED 1157s in the front blinker light and ZEVO amber LED 1156s in the rear blinker light. After doing so, I noticed that either the front directional-blinker light wasn't working or else the front emergency hazard light wasn't working properly - even though the bulb would illuminate in certain modes, forget what the issue was, and an owner instructed me to use a 1/2 inch plumbers fitting brush to clean out the front socket since he said it would be better than using small scraps of sandpaper that I already had, and after using the $3 Home Depot 1/2 fitting brush, all of the problems with improper flashing or blinking disappeared with the new LED bulbs.

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[jawn101]

Thanks guys. The front wiring is not modified and that blinker mod is not done. I can reproduce that strange blinking condition by jiggling the bulb around in the socket and it is now gone.

I also got into the socket with a dremel and a nylon brush head that perfectly filled the socket, so I don't think there is any corrosion to speak of in there. I did both sides. Even still, the directional indicators don't work at all with LEDs in these front sockets. If I swap back to regular bulbs, even while the flasher is going (confirmed it is a Napa EP35 electronic flasher) the circuit comes back to life.

What the....