LED help
 

I have a UCC cobra. I purchased the 1157 LED bulbs for the two front maker/blinkers in amber and 4 of the 1157 LED's for the rear blinkers/brake lights. All the bulbs came from super bright LED's. When I put all the LED's in, everything works as expected except the blinker don't blink in front or rear. I get a steady light. I ran through numerous scenarios with them and changed bulbs and such and this is what I discovered. As long as I have one of the original incandescent bulbs in on one side, everything works including the blinker. I can put it in the front marker or one of the rear tail lights (have the double round) and it all works. After doing some reading, it seems as though I need a flasher relay or resistor due to the LED's not pulling enough resistance to get the blinkers to work with all the LED's in. Hoping someone can help me out with this and send me in the right direction to get them all working. Thanks.

I think you are correct. The original relay triggers on heat generated by current flow and since LEDs don't draw enough current the relay is not triggered. Someone here likely knows the part number for what works. I think they are usually listed on the LED supplier web site also.

Did not see the previous post. The resistor increases current draw.

So from looking at this, I have the double round (two bulbs) on each tail light. The wiring running to them is just split at the lights. Would I need 2 resistors for each side (one resistor per bulb) or just a single resistor for each side. Then also one resistor for each front marker/blinker.

To cure the problem, I think you should be able to use a flasher made for LED's. I recently converted to LED's and have the same problem... no blinking.
I was advise to use a flasher made for LED's and ordered one, but have not yet received it to try it out.

So now thinking I can just change out the flasher relay? If so, what about the hazard relay, guessing that would need to be changed out as well. Should be able to use the same relay to replace it. Any thoughts?? Here is what I'm looking at

https://www.hipoparts.com/12v-heavy-...flasher-relay/

I don't think that flasher will work for you. I think it needs to say "for LED use" on it. I originally bought one that looked like the one you linked. It said that it was LED compatible but in the fine print it said "may require a resistor to work with LED's". It didn't flash. I should have the LED specific flasher I ordered by Wednesday and can let you know if it works.

BTW, like the originals, my car doesn't have 4-way flashers so don't know about a relay for that.

Switching from halogen to LED turn signals can introduce either a hyper-flash
or no flash/steady on condition with turn signals. The electro-mechanical
relays use load resistance from the halogens to switch on and off. LEDs
require only a fraction of power and hence produce very little load resistance.
You have (2) options here. Splice in a load resistor into each turn signal circuit
that mimics the halogen and fools the relay, or replace it with LED
compatible solid state relays. Option 2 is better and cheaper. Plus those
load resistors can get hot enough to melt plastic. You will need to replace
(2) relays. One for turn signals, the other for hazard lights. My relays
were (2) prong Tridon 552. If you have (3) prong relays.
Superbrightleds.com offers a (3) prong LED compatible relay.

1) CEC Industries LED Compatible (2) Prong Relay # EF32SS-R

Misc:
After switching to LED compatible relays, if you still experience a
no flash/steady on condition, the relay socket was reverse wired. Old
electro-mechanical relays are not polarity sensitive and hence the
technician who wired it did not care to check. No worries. Easily
corrected with a relay polarity adapter. The CEC Industries EF32SS-R
plugs into the adapter and together they plug into the relay socket.
If you have hazard flashers that relay may or may not need an adapter as well.

1) United Pacific Relay Polarity Adapter # 90650A

You can also create pigtail wires that go from relay into the wired socket.
Remember to cross connect both leads to correct polarity.

The above resolution will address almost every no flash issue using LED's.

Thanks for the info!

This is what I used.
Mustang Project - Product Display

For the rears, can LEDs be run in series vs. parallel now that the draw is much less.. may only require a single resistor. Also can LEDs be used in the instance when replacing a twin filament bulb?

Good luck,
Mike.

I have two different solutions coming in the mail over the next couple days. I will post the results and what works as soon as I figure everything out! Thanks for all the input!

I did get my LED specific flasher and it does blink.
There are many LED compatible flashers on ebay but I made sure that the one I bought had LED printed on the side.
One problem is that it no longer makes the clicking reminder that it's flashing so your only indication is your dash lights.

This is true. Solid state LED compatible relays do not have the telltale
"tick-tock" sound and blinker lights on the dash are your only indicator.

That said, if you can hear the click of a flasher relay over side pipes
and ear plugs then it's time to invest in more horsepower.:LOL: