Hazard Switch Wiring Diagram

SouthArk370Z · 11-10-2013, 07:37 PM

Quote:

Originally Posted by synolimit

... the 2nd/green to 12v?? Is power the BCM terminals? Looks like it from the manual since the battery has a wire feeding the BCM. Any idea on which is the LED when you turn the head lights on the button lights up? Will the 4th wire just get deleted since the new switch won't be able to blink or something when you turn them on?

Do NOT hook up power to the center terminals!!! Power for the switch is provided by the BCM. It is a "sinking" input - that terminal on the BCM is hot until you press the button and then it is sunk to ground potential.

I'm not sure about the light. I didn't see anything in the FSM whilst looking up the other info (doesn't mean it's not there, just that I didn't see it). What I would try is activating the switch and taking some readings with a voltage meter. One of the outside terminals should have 12V when the flashers are on (may be pulsing) and the other outside terminal will probably go to ground.

synolimit · 11-10-2013, 08:07 PM

Quote:

Originally Posted by SouthArk370Z

Do NOT hook up power to the center terminals!!! Power for the switch is provided by the BCM. It is a "sinking" input - that terminal on the BCM is hot until you press the button and then it is sunk to ground potential.

I'm not sure about the light. I didn't see anything in the FSM whilst looking up the other info (doesn't mean it's not there, just that I didn't see it). What I would try is activating the switch and taking some readings with a voltage meter. One of the outside terminals should have 12V when the flashers are on (may be pulsing) and the other outside terminal will probably go to ground.

No I mean the new switch has a led prong, ground prong, and 12v/power prong. I'd only be hooking the existing wires to the new switch.

So to start and be safe...hook the middle 2 wires to the new switch marked ground and 12v. Only thing is my plug isn't labeled with numbers and my wires are different colors. Ill do some testing first I guess.

SouthArk370Z · 11-10-2013, 08:42 PM

Quote:

Originally Posted by synolimit

No I mean the new switch has a led prong, ground prong, and 12v/power prong. I'd only be hooking the existing wires to the new switch.

So to start and be safe...hook the middle 2 wires to the new switch marked ground and 12v. Only thing is my plug isn't labeled with numbers and my wires are different colors. Ill do some testing first I guess.

Ah. Sorry about the confusion.

Should be pretty easy to verify the stock wiring. One of the wires (the one from the BCM) should be hot (12V) and the associated ground wire should have continuity to ground. For the light, one of the wires should have 12V (possible pulsing) when the flashers are turned on and the associated ground wire should have continuity to ground.
You can check the grounds with the car off. I think the BCM power to the switch is on all the time (so you can operated the flashers when the car is off).

synolimit · 11-10-2013, 09:29 PM

Quote:

Originally Posted by SouthArk370Z

Ah. Sorry about the confusion.

Should be pretty easy to verify the stock wiring. One of the wires (the one from the BCM) should be hot (12V) and the associated ground wire should have continuity to ground. For the light, one of the wires should have 12V (possible pulsing) when the flashers are turned on and the associated ground wire should have continuity to ground.
You can check the grounds with the car off. I think the BCM power to the switch is on all the time (so you can operated the flashers when the car is off).

No worries

Ok please don't make fun! My light test stopped working so I made this haha and I don't have a volt meter. Here's what I found out...I put one nail to a ground source and the other nail touched all the harness wires for both buttons...

Hazards...

Orange wire- does nothing ever (possible ground since it connects to the thick black one on the main harness)
Green wire- with the car on or off, when my light tester touches the green wire the hazards turn on like they should (a circuit is being completed using the light bulb)
Black wire- does nothing ever (possible ground)
Light blue wire- with key turned on it does nothing, with headlights on the tester light lights up (the button LED wire)

Synco

Green w/ white stripe- nothing ever (possible ground)
Dark blue wire- with key turned on it does nothing, with headlights on the tester light lights up (the button LED wire)
Black w/ red stripe- with the car on the tester light lights up
Black w/ yellow stripe- does nothing ever (possible ground)

So with only a 3 prong switch, which ground wires out of the possibly 2 do I use?

SouthArk370Z · 11-10-2013, 09:48 PM

Quote:

Originally Posted by synolimit

Ok please don't make fun! My light test stopped working so I made this haha and I don't have a volt meter. Here's what I found out...I put one nail to a ground source and the other nail touched all the harness wires for both buttons...

Not the best solution but sometimes ya gotta do what ya gotta do.

Quote:

Originally Posted by synolimit

Hazards...
Orange wire- does nothing ever (possible ground since it connects to the thick black one on the main harness)
Green wire- with the car on or off, when my light tester touches the green wire the hazards turn on like they should (a circuit is being completed using the light buld)
Black wire- does nothing ever (possible ground)
Light blue wire- with key turned on it does nothing, with headlights on the tester light lights up (the button LED wire)

Orange & Black = ground. One of those will be the switched side of the switch. In this case, that wire will be grounded, too. With a meter, you could measure resistance to ground and verify. To tell which one is the switch, you need an ohmmeter or continuity checker.
Green. That will be the wire from the BCM.
Lt Blue = illumination. If the light is normally on with the dash lights (I haven't noticed mine), then I think you got that one right, too. It would be nice to be able to check the voltage as the dash lights are adjusted to confirm this.

Quote:

Originally Posted by synolimit

Synco
Green w/ white stripe- nothing ever (possible ground)
Dark blue wire- with key turned on it does nothing, with headlights on the tester light lights up (the button LED wire)
Black w/ red stripe- with the car on the tester light lights up
Black w/ yellow stripe- does nothing ever (possible ground)

Grn/Wht & Blk/Yel = ground. See above.
Drk Blue. Same as Lt Blue above.
Blk/Red. Should be coming from the BCM but I haven't look at the schematic so it may be Ign.

A cheap multimeter from the auto parts store (or WalMart, or Radio Shack, or ...) will be good enough for what you are doing and they can be found for $5-20.

synolimit · 11-10-2013, 10:14 PM

Quote:

Originally Posted by SouthArk370Z

Not the best solution but sometimes ya gotta do what ya gotta do.

Orange & Black = ground. One of those will be the switched side of the switch. In this case, that wire will be grounded, too. With a meter, you could measure resistance to ground and verify. To tell which one is the switch, you need an ohmmeter or continuity checker.
Green. That will be the wire from the BCM.
Lt Blue = illumination. If the light is normally on with the dash lights (I haven't noticed mine), then I think you got that one right, too. It would be nice to be able to check the voltage as the dash lights are adjusted to confirm this.

Grn/Wht & Blk/Yel = ground. See above.
Drk Blue. Same as Lt Blue above.
Blk/Red. Should be coming from the BCM but I haven't look at the schematic so it may be Ign.

A cheap multimeter from the auto parts store (or WalMart, or Radio Shack, or ...) will be good enough for what you are doing and they can be found for $5-20.

Yeah I know haha.

So do the grounds matter being one switch and one not?

I'll buy a meter but I guess I'm planning to..

Green=12v prong on switch
Lt blue=LED prong on switch
Orange and black or just one or the other=ground prong on switch

Grn/Wht and Blk/Yel or just one or the other=ground prong on switch
Drk Blue=LED prong on switch
Blk/Red=12v prong on switch

SouthArk370Z · 11-10-2013, 10:46 PM

A ground is a ground but which one of those grounds goes to the switch is important when you do your rewiring since you don't seem to be sure that the switch pins are in the middle of the connector and the illum pins are on the outside as per the FSM I have.

You seem to be adept at Redneck Engineering, so run a hot wire to one side of your test lamp (use a fuse) and a wire from one side of the switch (the uninstalled switch, not the wiring) to ground. Wire the other end of the test light to the other terminal on the switch. You should have a series circuit from hot to light to switch to ground. Push the button and the light should come on. This will verify the switch terminals and you should be able to tell which wire it is from that.

Just thought of this and don't want to edit all that above: You can use the light for the ground wire and run the hot straight to the switch.

synolimit · 11-11-2013, 03:55 AM

Quote:

Originally Posted by SouthArk370Z

A ground is a ground but which one of those grounds goes to the switch is important when you do your rewiring since you don't seem to be sure that the switch pins are in the middle of the connector and the illum pins are on the outside as per the FSM I have.

You seem to be adept at Redneck Engineering, so run a hot wire to one side of your test lamp (use a fuse) and a wire from one side of the switch (the uninstalled switch, not the wiring) to ground. Wire the other end of the test light to the other terminal on the switch. You should have a series circuit from hot to light to switch to ground. Push the button and the light should come on. This will verify the switch terminals and you should be able to tell which wire it is from that.

Just thought of this and don't want to edit all that above: You can use the light for the ground wire and run the hot straight to the switch.

I'm sure your right and it would make sense. Middle 2 (1 and 2) are for the switch on/off of hazards and s-mode and outside 2 (3 and 4) are for when the lights come on so you can see the button at night.

Lol hey I turn a wrench great, just never learned, studied, read up on electronics and stuff. If the manual doesn't say red to green, blue to black etc I'm lost.

Took me a minute to understand all that but I already know what my terminals will be for the new switch so I don't need to do all that (unless I'm totally lost). I'm getting confused because we might be talking about 2 different things.

Here's my switch...

Box says 1 prong for 12v, 1 prong for ground, and 1 prong LED (it's the single copper one)

So if grounds a ground then just hook the orange and black together and run them to the ground prong on the new switch and Blk/yel and gre/wht together on the other switch?

But I feel that's wrong or why else would nissan make a 4 wire switch when 3 would do? I think I'll need to leave 1 ground wire taped up. the inside of the new switch has the LED able to be grounded using the negative side of the LED to the ground prong already in place?

I guess using just one ground would mean unlike OEM where I'll have a button light off during the day and on at night with the headlight, the new switch and LED I'll have to decide if its a 24/7 on light or only on when I turn the headlights on...

SouthArk370Z · 11-11-2013, 07:32 AM

Quote:

Originally Posted by synolimit

I'm sure your right and it would make sense. Middle 2 (1 and 2) are for the switch on/off of hazards and s-mode and outside 2 (3 and 4) are for when the lights come on so you can see the button at night.

Ah. For some reason I was under the impression that your wiring was different than the '09 FSM I'm using. Apparently it's just the wire colors.

Quote:

Originally Posted by synolimit

... I'm getting confused because we might be talking about 2 different things.

There does appear to be some miscommunication here. Not unusual on the Intertubes. I think the main problem is my mistaken belief that your wiring was different.

Quote:

Originally Posted by synolimit

So if grounds a ground then just hook the orange and black together and run them to the ground prong on the new switch and Blk/yel and gre/wht together on the other switch?

You only need one of the grounds (assuming the other end of both wires is a good ground, which it should be). I'd go ahead and connect both ground wires. If you only connect one, use the largest wire (but I'm guessing they are the same size).

Quote:

Originally Posted by synolimit

But I feel that's wrong or why else would nissan make a 4 wire switch when 3 would do? I think I'll need to leave 1 ground wire taped up. the inside of the new switch has the LED able to be grounded using the negative side of the LED to the ground prong already in place?

It is "good engineering" to isolate computer circuits from "external" circuits but that's a bit of overkill in a modern car where you have excellent grounding. Plus, this is a digital I/O line, not an analog sensor, and noise is not as critical when you are looking for on/off. Theoretically, separate circuits would be best; in practice, it doesn't make a lot of difference. I'm guessing that the reason Nissan did it their way is: If the ground for 3-terminal switch has high resistance (eg, corroded connection), then it would be possible for the power going to the light to feed into the switch circuit (and vice versa) - as long as you have a good ground, that shouldn't be a problem. Even with a poor ground, it shouldn't be unsafe, to you or the car, in your situation. It might not work right, but it shouldn't do any harm.

Quote:

Originally Posted by synolimit

I guess using just one ground would mean unlike OEM where I'll have a button light off during the day and on at night with the headlight, the new switch and LED I'll have to decide if its a 24/7 on light or only on when I turn the headlights on...

As long as you have a good ground, the light should work properly. The "other" end of both wires are grounded and at the same potential, so, electrically, the terminal ends are the same.

synolimit · 11-11-2013, 06:19 PM

Quote:

Originally Posted by SouthArk370Z

Ah. For some reason I was under the impression that your wiring was different than the '09 FSM I'm using. Apparently it's just the wire colors..

I'm hoping so. I mean I know the power of both are in for on/off and out for illum and 1-2-3-4 are all in the same spots on both clips. If a grounds a ground it shouldn't matter although if I did only use 1 I'd have to use the one for function of on/off and not illum.

Quote:

Originally Posted by SouthArk370Z

You only need one of the grounds (assuming the other end of both wires is a good ground, which it should be). I'd go ahead and connect both ground wires. If you only connect one, use the largest wire (but I'm guessing they are the same size)..

The wires on the pig tail are all the same size. The wires on the main harness that the pig tail clips into are all smaller but one. The one that's different is even bigger than the wires in the pig tail. That's the one that the orange wire attaches to on the hazards which appears to be a ground and its on the outside which possibly means the ground for the illum of the hazard LED. But that's odd because the ground on the outside for the s-mode illum is a really small wire like all the main harness wires are. The big wire I'm talking about is solid black though. Since all my body panels are off you can see every ground bundle of 10 or so all over the car are all solid black wires of different thicknesses.

Quote:

Originally Posted by SouthArk370Z

It is "good engineering" to isolate computer circuits from "external" circuits but that's a bit of overkill in a modern car where you have excellent grounding. Plus, this is a digital I/O line, not an analog sensor, and noise is not as critical when you are looking for on/off. Theoretically, separate circuits would be best; in practice, it doesn't make a lot of difference. I'm guessing that the reason Nissan did it their way is: If the ground for 3-terminal switch has high resistance (eg, corroded connection), then it would be possible for the power going to the light to feed into the switch circuit (and vice versa) - as long as you have a good ground, that shouldn't be a problem. Even with a poor ground, it shouldn't be unsafe, to you or the car, in your situation. It might not work right, but it shouldn't do any harm..

Well since I'm just plugging into the main harness in a way, the other ends where ever they go, the engineers of the grounds and such have already been taken care of. I just need to know now which wire goes where on the new aftermarket switch. O I gotcha. Kinda like new homes doing isolated water lines for everything in the house. No pressure drops and if there is a leak it can be turned off easy without draining the whole houses water lines.

Quote:

Originally Posted by SouthArk370Z

As long as you have a good ground, the light should work properly. The "other" end of both wires are grounded and at the same potential, so, electrically, the terminal ends are the same.

Why would I need a ground using the factory wires just plugged into the new switch? Or are you talking about a good ground within the new switch?

SouthArk370Z · 11-11-2013, 06:33 PM

Quote:

Originally Posted by synolimit

The wires on the pig tail are all the same size. The wires on the main harness that the pig tail clips into are all smaller but one. The one that's different is even bigger than the wires in the pig tail. That's the one that the orange wire attaches to on the hazards which appears to be a ground and its on the outside which possibly means the ground for the illum of the hazard LED. But that's odd because the ground on the outside for the s-mode illum is a really small wire like all the main harness wires are. The big wire I'm talking about is solid black though. Since all my body panels are off you can see every ground bundle of 10 or so all over the car are all solid black wires of different thicknesses.

In practice, it doesn't really matter. The bigger the wire, the better, but the current through the light is minimal and the current through the switch is almost zero.

Quote:

Originally Posted by synolimit

Why would I need a ground using the factory wires just plugged into the new switch? Or are you talking about a good ground within the new switch?

When I say "good ground" I mean "low resistance ground".

Do you have a schematic/diagram showing how the switch is wired internally. One of the switch terminals probably powers the light (internally) and the third leg is the ground for the light, but, w/o a diagram, impossible to be sure from here.

synolimit · 11-11-2013, 07:15 PM

Sure do...

SouthArk370Z · 11-11-2013, 10:00 PM

Quote:

Originally Posted by synolimit

Sure do...

To wire that switch as a remote for the flasher button, connect the BCM wire to 3 and connect 1 & 2 to ground. The way the switch/light is configured the light will either be on ALL the time (if BCM wire is connected to 2) or never (with BCM to 3). Edit: Since the light won't work anyway, no sense in hooking up 1.

It may work if you connect BCM to 3 and only connect 1 to ground; nothing connected to two. This will put the LED in series with the BCM/ground which may give the circuit too much resistance. Worth a try. Can't harm anything. Light would be on when the switch is on; no flash.

synolimit · 11-11-2013, 10:06 PM

Quote:

Originally Posted by SouthArk370Z

To wire that switch as a remote for the flasher button, connect the BCM wire to 3 and connect 1 & 2 to ground. The way the switch/light is configured the light will either be on ALL the time (if BCM wire is connected to 2) or never (with BCM to 3). Edit: Since the light won't work anyway, no sense in hooking up 1.

It may work if you connect BCM to 3 and only connect 1 to ground; nothing connected to two. This will put the LED in series with the BCM/ground which may give the circuit too much resistance. Worth a try. Can't harm anything. Light would be on when the switch is on; no flash.

If no harm comes I'll go try now as I just got home with the switches.

SouthArk370Z · 11-11-2013, 10:16 PM

Quote:

Originally Posted by synolimit

If no harm comes I'll go try now as I just got home with the switches.

If it works, the light may be dim. There is a resistor in the BCM that limits current for the sinking circuit.

11-10-2013, 10:46 PM	#22 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	A ground is a ground but which one of those grounds goes to the switch is important when you do your rewiring since you don't seem to be sure that the switch pins are in the middle of the connector and the illum pins are on the outside as per the FSM I have. You seem to be adept at Redneck Engineering, so run a hot wire to one side of your test lamp (use a fuse) and a wire from one side of the switch (the uninstalled switch, not the wiring) to ground. Wire the other end of the test light to the other terminal on the switch. You should have a series circuit from hot to light to switch to ground. Push the button and the light should come on. This will verify the switch terminals and you should be able to tell which wire it is from that. Just thought of this and don't want to edit all that above: You can use the light for the ground wire and run the hot straight to the switch. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

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