I can tell you that in retrospect I feel very lucky I got our 73 Mustangs' LED taillight panels to work in place of their original 1157 incandescent bulbs. I also replaced all the 1157 incandescent bulbs on our 1969 Shelby GT500 with a blending of different makes of LED bulbs. For the Shelby, because we had a lot of bulbs going through its turn signal flash sequencer, there was enough current demand/draw to allow the oem TS flashers to work. But, I had to play with two different style LED bulbs before the flash sequencer timing from one light to the other would work with the kind of delay between flashes that looked good. When I used all the same bulb make the flashing sequence would be erratic, goofy looking. I just happened to have two different LED lights on hand, and my beginning to mix and match them was more of a "Hail Mary" move on my part, and one that ended up working well. The difference in how bright the LEDs are vs the original incandescent bulbs is what inspired me to keep trying different approaches so I could keep the LEDs in place. I was willing to get an electronic flasher if I would have had to, but I really did not want to have to replace the flashers. The front Turn Signal bulbs are still incandescent bulbs with filament units, which likely is part of why there is still enough current used for the turn signal circuit to allow their bi-metallic strip to work properly.
So far, this has not helped you much, and I know that. This is still a bit more art based on science for me. For example, on our 1973 Mach 1 I had to install electronic TS flashers for its rear taillight LED panels to work, whether I used flash sequencing or not. But, on our 1973 Mustang Convertible I was able to keep the original TS flashers in place. I determined the difference was because I also installed LEF lights on the front TS sockets on the Mach 1, but kept the oem 1157 bulbs in lace for the 73 vert. The 1157 bulbs drew enough current that the oem flashers worked fine But, on the Mach 1 using all LED front and rear reduced the current draw to a point so low that the oem flashers did not get the amperage needed to cycle the internal bi-metallic strip what causes the flashing action. All that said, I did not know there were so many kinds of electronic flashers. And I do not know the magic combination that will work for all circuits. That was no big deal until the other day a friend in our area told me he wanted to use LED lights in his 1970 Mercury cyclone taillights, We have not found anyone who offers a replacement taillight panel, like we have with our 73 Mustangs. So, he has decided to just pop in some LED lights to replace his 1157 bulbs, much like I did with our 69 Shelby. But, his taillight bulb array is only two bulbs per side, as opposed to 3 bulbs per side on our Shelby - which means his results will not be the same as mine. Further, he wants to have flash sequencing, something not offered with the 70 Cyclone, where he has only two pods per side with bulbs in them. The 3rd pod has red reflective material and houses the backup light bulb. So I can't go by what our Shelby uses.
I decided my best bet is to tig up a bench test system where I can work with both LED lights and 1157 bulbs to see what flashers would work with a 3 stage flash sequencer, although I will only be using two flash stages. I got a 0-18 volt, 0-30 amp DC adjustable power supply, a flash sequencer for First Generation Cougars, Shelbys, and Thunderbirds (solid state replacement, not electro-mechanical relays), 10 1157 sockets, 10 1157 incandescent bulbs, and 8 LED 1157 lights. I now have a morass of wires with alligator clips connecting various sockets and bulbs in an effort to simulate how we need to connect everything to make what will certainly be a Franken-Light setup so we can get him his LED taillights and 2 cycle sequence flashing using a 3 stage sequencer.
Why am I sharing all this info? Here is the deal. If you get to the point where you are done playing the "try this, try that" game. if you ship me you flashers and LED units I am willing to set things up on my little test bench and see what works best. Did you want turn signal flash sequencing? If not, things will be easier to work with. If so, that is fine, but once my friend begins to assemble his lighting system he will be purchasing the flash sequencer I purchased to test with (I think it was about $200 or so). Because I undertook this project very recently I have not yet worked out what wires go where with the sequencing, and because it is going to be using only two of its three output connections I am going to end up playing around a lot just to see if I can get it to flash like he wants it to (flash rate is not adjustable on its circuit card, it may vary depending on how much current is flowing through the bulbs/LEDs).
Anyway, if you would like me to try to see which flasher works, and the polarity needed with a series of 1157 LED light bulb replacements, let me know. I have decided to get a different set of 1157 sockets as the ones I got are cheaply made and tend to allow the terminal ends inside the socket to ground out on the socket shell - lots of fun seeing that... Other than that, and in fact despite that, I would be more than happy to help you out like that. If interested email me at
[email protected]. The only cost you will incur would be for the parts (LED lights, sequencer if you want to use one, TS flasher(s) and mailing. As an alternative, as I work my way through the project I have on hand I could simply let you know what seems to be working best out here with whatever LED 1157 units I am using with or without the sequencer, and have you purchase the brands and models I have on hand from the vendor I got them from.
Up to this point I have just been puttering here and there on the project, as the Cyclone is not anywhere near ready to be worked on, especially in his cold garage up here in Snow Country. But, knowing I may be able to help you come up with the right mix of bulbs and flasher(s) has inspired me to get back on the project as opposed to doing other "stuff" to keep me busy in Winter Hibernation for our pony cars. It is finally time for me to begin to work out the LED, flasher, sequencer project so I can free up our power supply and various other parts being used.