How do turn signals work?

JoshNZ

JoshNZ

TJ Enthusiast
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Jan 15, 2019
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New Zealand
Although there is likely many answers to this question (thinking BMW memes) I literally just want to know how turn signals work.

Japan, NZ, Aus, Europe(?) etc have a separate orange light as the indicator. So flick your stalk, flasher relay sends a flash to the bulb in said orange lights. Front, side, and rear.

US cars tend to often have the turn signal and tail/brake light as one.
So how does this work when taillights or brakes are on?

I'm after an answer that's probably pretty obvious to you all, but not obvious enough to me
 
JoshNZ said:
Although there is likely many answers to this question (thinking BMW memes) I literally just want to know how turn signals work.

Japan, NZ, Aus, Europe(?) etc have a separate orange light as the indicator. So flick your stalk, flasher relay sends a flash to the bulb in said orange lights. Front, side, and rear.

US cars tend to often have the turn signal and tail/brake light as one.
So how does this work when taillights or brakes are on?

I'm after an answer that's probably pretty obvious to you all, but not obvious enough to me
Click to expand...
huh?
 
JoshNZ said:
Although there is likely many answers to this question (thinking BMW memes) I literally just want to know how turn signals work.

Japan, NZ, Aus, Europe(?) etc have a separate orange light as the indicator. So flick your stalk, flasher relay sends a flash to the bulb in said orange lights. Front, side, and rear.

US cars tend to often have the turn signal and tail/brake light as one.
So how does this work when taillights or brakes are on?

I'm after an answer that's probably pretty obvious to you all, but not obvious enough to me
Click to expand...

Still works the same way, just switches the same bulb over to the flasher circuit.

Edit: Most modern cars don't have flasher relays. Everything is handled via computer(s) i.e. a Body Control Unit or something of similar nomenclature.
 
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The USA uses four separate circuits, one for the tail lights, one for the third brake light, and one for each turn signal/brake light.

The rest of you use four different circuits, one for tail lights, one for all three brake lights and and one for each turn signal.

Both versions may have the turn signal circuits connected prior to the turn signal switch, and I guess the USA brake light version could be seen as all three brake lights also connected prior to the turn signal switch.

That's the simple explanation. Details about it are more difficult.
 
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I was getting creative with flasher units pulsing double throw, double pole switches to ground the brake light circuit when the brake/taillights are on etc. I knew there would be a simpler answer, now I (kinda) know.

Thanks @JEEPCJTJ, care to give more detail for my interests sake?
 
JoshNZ said:
I was getting creative with flasher units pulsing double throw, double pole switches to ground the brake light circuit when the brake/taillights are on etc. I knew there would be a simpler answer, now I (kinda) know.

Thanks @JEEPCJTJ, care to give more detail for my interests sake?
Click to expand...


I'm glad you found something that helps. More than what I posted was too much for me to handle.
 
I think we need all turn signals in the US to be an orange/ amber color. I hate it when someone is turning and I can’t tell if their braking or not. It’s especially annoying if their third brake light doesn’t work.
 
JoshNZ said:
US cars tend to often have the turn signal and tail/brake light as one.
So how does this work when taillights or brakes are on?
Click to expand...

On older cars the bulb in the tail light has two filaments. One is brighter and is the brake light, and the turn signal while the other filament is the running light.

When the signal is on and the brake is applied, the brake light filament flashes. The other tail light is still lit up, so having the other side flash with the same bulb that is also the brake light isnt a big deal.
 
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