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1 flasher 2 flasher red flasher blue flasher

WILDHORSES

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Am I correct that when Bronco switched to emergency flasher to the column the wiring harness went from having 2 flashers to just 1? I only find 1 each on my 76 & 77 so I'm assuming that correlates to the emergency flasher. Never paid that much attention to these but I'm working on LED kits and no sense in loading up the kits with 2 flashers if half the Broncos only use 1. Thanks!

Jim
 

tasker

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My Flasher on dash has two....the harness i have for a 76/77 has one
 

Slowleak

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You are not looking hard enough. It still has two and they show on the factory wiring diagram. The one with red/white wires going to it is for the hazards. The turn signal flasher has a blue wire and yellow wire. Unplug the one you found and try the hazards and turn signals.
When I switched my ‘77 to LED’s I only had to replace the turn signal flasher. The hazards worked with the old flasher.
Here is the diagram from SeaBiscuit
137bb6afb910ccdb0b96df7e476cd081.png
 
OP
OP
WILDHORSES

WILDHORSES

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You are not looking hard enough. It still has two and they show on the factory wiring diagram. The one with red/white wires going to it is for the hazards. The turn signal flasher has a blue wire and yellow wire. Unplug the one you found and try the hazards and turn signals.
When I switched my ‘77 to LED’s I only had to replace the turn signal flasher. The hazards worked with the old flasher.
Here is the diagram from SeaBiscuit
You are right, I found it! The emergency flasher is tucked in way better. Which leads me to this question. Why do the emergency flashers work for LEDs without swapping the flasher but the turn signals must have the flasher swapped? What don't I understand about this?

Jim
 

Slowleak

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You are right, I found it! The emergency flasher is tucked in way better. Which leads me to this question. Why do the emergency flashers work for LEDs without swapping the flasher but the turn signals must have the flasher swapped? What don't I understand about this?

Jim

I’m not sure, but my theory is that since the emergency flasher causes all 4 lights to flash, it draws enough power to trip the flasher. The turn signal only uses half as much power.
 

Oldtimer

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I suspect that with all 4 led lights connected to emergency flasher there is sufficient load to activate conventional flasher, but you need to confirm before pulling 2nd ked flasher from kit.
 

Yeller

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Jim, that’s an easy question, I probably have a dumb answer :p:p

The turn signal flasher uses load from the bulbs to generate the flashing action so it stops flashing or gets very slow when a bulb burns out you know it is happened. LED’s draw less energy so the old school flasher doesn’t work, that’s why if you add a resistor in line with and LED it will flash. It’s just so you have an analog computer telling you a bulb out like open up on the screen in a modern car.

The hazard flasher is self loading, it will flash if it is no bulbs in the circuit or 20, it doesn’t care, it just flashes. On the hazard there is no need for it to do a load check to warn you of a vehicle issue, it just needs to flash.

On vehicles without a second flasher for the hazards, they typically have a computer monitoring bulbs and use a self loaded flasher.

I said it would be a dumb answer, well not really dumb, just some old school, low tech vehicle condition monitoring.
 
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WILDHORSES

WILDHORSES

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I have confirmed the emergencies work without the LED flasher. I may just pull two blubs and see if they still work to try and prove the load example. Thanks for the input.

Jim
 

jmhend

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Jim, I replace all of my bulbs to LED bulbs and only had to change the emergency flasher. One thing that I did not test and now I am wondering if if you take the emergency flasher and plug it into the turn signal flasher does the problem follow the new switch? I will try to do the same testing on my own now based on curiosity.

I have replaced my turn signal flasher several times and finally moved the hazard flasher to the turn signal on another bronco and the old hazard flasher works like a champ.
 

jamesroney

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I suspect that with all 4 led lights connected to emergency flasher there is sufficient load to activate conventional flasher, but you need to confirm before pulling 2nd ked flasher from kit.
@Oldtimer Does your MPC show a different part number for the turn signal flasher versus the emergency flasher?

@Yeller says that the hazard flasher is "self loading" but that can only happen if the flasher itself has a current path to ground. Obviously the plastic flashers can't do that. I'm going to be surprised if I learn that the hazard flasher works different than the turn signal flasher. But then a lot of things would start to make sense.

I suspect that you can substitute a "normal" flasher in either location. The hazard circuit has plenty of bulbs on it. But you wouldn't be able to use a hazard flasher in the turn signal location. The Seabiscuit diagram shows a slightly different internal connection in the schematic. I'm skeptical of this self loading thing, otherwise the emergency flasher should cycle whenever it has power applied. (which is always)

Someone must know this?
 

Oldtimer

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Different part numbers, so internals MAY be different?

1726854998088.png


Per NumberDummy:

C5AZ-13350-B .. (BLUE) T/S Flasher (Motorcraft/Industry# SF-224).

D1FZ-13350-A .. (GREEN) Emergency Warning & T/S Flasher with trailer tow (Motorcraft/Industry# SF-552-B)
 
Last edited:

Oldtimer

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Looking at SeaBiscuit's schematic,
turn signal flasher is N.O. (normally open) and
emergency flasher is N.C. (normally closed)

1726887363015.png
 

ba123

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@Oldtimer Does your MPC show a different part number for the turn signal flasher versus the emergency flasher?

@Yeller says that the hazard flasher is "self loading" but that can only happen if the flasher itself has a current path to ground. Obviously the plastic flashers can't do that. I'm going to be surprised if I learn that the hazard flasher works different than the turn signal flasher. But then a lot of things would start to make sense.

I suspect that you can substitute a "normal" flasher in either location. The hazard circuit has plenty of bulbs on it. But you wouldn't be able to use a hazard flasher in the turn signal location. The Seabiscuit diagram shows a slightly different internal connection in the schematic. I'm skeptical of this self loading thing, otherwise the emergency flasher should cycle whenever it has power applied. (which is always)

Someone must know this?
This sounds right to me.

On my Ron Francis panel, the hazard flasher did NOT work for LEDs. I had to get a United LED flasher for both turn as well as Hazard and I had to connect them to ground.
 

Brush Hog

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When I switched to LED bulbs I had to get some doohickey that reversed the polarity on my flasher for the hazards. And I had 2 flashers that were bad right out of the box. Took a while to figure out that was the problem.
 

ba123

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When I switched to LED bulbs I had to get some doohickey that reversed the polarity on my flasher for the hazards. And I had 2 flashers that were bad right out of the box. Took a while to figure out that was the problem.
Not "bad" but LEDs are polarity sensitive, whereas regular filament bulbs are not.

The United ones are nice because they come with a polarity switcher in the package. The other alternative to reversing polarity is to reverse the polarity on your wiring to your bulbs but that's more work.
 

Brush Hog

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Not "bad" but LEDs are polarity sensitive, whereas regular filament bulbs are not.

The United ones are nice because they come with a polarity switcher in the package. The other alternative to reversing polarity is to reverse the polarity on your wiring to your bulbs but that's more work.
No they were “bad” as in did not work. Like a lot of new parts these days. I like that there are ones with the polarity switcher in the package. I had to order separately.
 
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