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I don't have anything to shoot decent video with. But the rear LEDs function perfect with regular bulbs in the front, but all four rapid flash with LEDs in front. The parking lights light up fine (and look great in my new clear corners), and the resistor heats up when flashing so I know it's wired correctly.

For the time being I just put the regular bulbs back in the front.
Ah.

That wasn't what I visualized from your post. Sorry!

That's one reason why I went with a LED-compatible flasher for Ruby.

But the other thing is - a 10 ohm resistor won't pull enough quite to replace a 3157 bright filament, it needs to be closer to 6 ohms. And 50W to dissipate enough heat on the back. And I'd bolt it to sheet metal somewhere with some heat sink compound between to help pull the heat off. And that really defeats one of the major reasons to use LEDs for me ... the reduced power consumption. (The other is the instantaneous on for the rear brake lights.)

(Math time! A 3157 bright filament is rated at 27 watts at 13.8V. At 13.8, that's a hair's width shy of 2 amps. To pull 2 amps at 13.8V, you need a 6.9 ohm resistor. So the 10 ohms isn't quite enough around, since I doubt the LED is actually pulling the rest of the current needed. So lower resistance resistors, closer to 6 ohms - 7 should do just fine, or maybe even 8! - or a LED compatible flasher. Cougars don't quite have that problem, due to the extra turn signal bulb up front.)

RwP
 

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Actually, it's worse than that.

A tungsten filament in the 3157 is about4 ohms cold, so it draws even more current.
 

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I would disregard it though, it slowed down hyperflash but still blinked faster than normal for some reason, at a rate right between normal and full hyperflash.
It worked well for my Cougar. I have the Zevo LED at all four corners. The flash is faster than stock, I'd prefer it a tad faster anyway though. I did end up putting a resistor on each rear taillight light to solve the cruise control issue. Everything works fine now and happy with the setup.
 

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The standard flasher is a bi-metallic strip flasher.


It flashes proportional to the load.

The led capable one is a timer circuit and a relay.
 

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Our flasher is not a bi-metallic strip flasher, it’s a relay controlled by a timer IC. The mod Kenz and I did was take away the load sense trace going to the IC that changes the sequence from normal to hyper.
 

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OK; that's an awfully expensive way to do it if you're going to emulate the bimetallic strip anyway.

I've never dissected one of ours, but the metal can ones still are, last I checked, a few years ago.
 

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This is the relay in my car, an '89. I can't find an LED compatible replacement. I used 8 ohm resistors which work on the rear, it's just the front that's an issue. I don't know why the front circuit would be different. I'll try 6 ohms in front and see how it does. Thanks.
I didn't find a direct plug in either.

HOWEVER.

Functionally, this unit https://www.superbrightleds.com/moreinfo/flashers-load-resistors/ep27l-led-bulb-electronic-flasher/784/838/ will do, but it's pinned out differently.

Luckily, it's the same spacing etc. as the Bosch 40A auto relay; so a relay socket fits fine.

The electrical wiring is at the same link.

I replaced the pigtail with a Bosch relay socket, and plugged that EP27L right in. It works a treat.

My biggest problem was keeping straight which L was which, and how the + and - wired up. The SBL drawing is the bottom of the flasher module; if you are wiring the Bosch socket, use the wiring side of the socket to locate them.

One possibility is to gut an old Ford flasher and wire in a pigtail; or put .187 and .250 FastOn style male connects on the end of the relay pigtail and plug THAT into the current socket.

RwP
 
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