Backup lights

[crash457]

agreed, if you were concerned of power consumption over-rating the switch. Truth be told, it'd be advisable to use all the aux switches as control on a bank of relays to ensure power is under the hood and not hurting the factory wiring- but its overkill on simple/small circuits like the S2's I used.

The way I wired it, I may chase the trailer plug up to the front of the vehicle (since I used the center pole of the round trailer hitch to find reverse "on" vs. the 24? gauge wiring on the tail lights) and simply tap an aux switch into it. Additionally, if the trailer you have DOES indeed have reverse lights, you'd be turning those on manually if needed as well.

Agree that you don't need a relay if you just want to have them come on with the reverse lights, but if you want to trigger with the back up lights or via an up fitter switch when not in reverse, then a relay is needed. If you just tie them together as was suggested, you will have two problems. First, you will be back feeding voltage through the up fitter switch when the truck is in reverse. Second, you will be sending voltage to the factory reverse lights when the up fitter switch is on and the truck is not in reverse.

 

[halogrinder]

Agree that you don't need a relay if you just want to have them come on with the reverse lights, but if you want to trigger with the back up lights or via an up fitter switch when not in reverse, then a relay is needed. If you just tie them together as was suggested, you will have two problems. First, you will be back feeding voltage through the up fitter switch when the truck is in reverse. Second, you will be sending voltage to the factory reverse lights when the up fitter switch is on and the truck is not in reverse.

Back feeding power through an open switch is no issue. Turning on the reverse lights on the tail lights seems like it has no negative effects.

 

[crash457]

Back feeding power through an open switch is no issue. Turning on the reverse lights on the tail lights seems like it has no negative effects.

And if the switch is on and you put the truck in reverse, your back feeding voltage into a switch that is not open.

Why not just wire it up properly?

Is this the kind of low rent engineering that BWM does?

 

[halogrinder]

And if the switch is on and you put the truck in reverse, your back feeding voltage into a switch that is not open.

Why not just wire it up properly?

Is this the kind of low rent engineering that BWM does?

You like to argue, I like you- we can be friends

Lemme axe you a question
What happens when you have a low current 12v switch that is off- and the open leg has 12v currently on it and you turn it on?
From reverse activated 12v>>>>> switch <<<<<12v from truck
Do the pixies go up stream like a spawning fish? NO.

I do believe it would be acceptably wired correctly, since the trailer plug will be fused as well.

Please, for the record tell the class what happens when you use Terminal 87a on a standard 5 pin Bosch style relay? What would happen if you had power there and the control side was collapsed? I can answer it for you if you'd like.
Nothing.



Next argument- "I think the sky is blue"

 

[crash457]

You like to argue, I like you- we can be friends

Lemme axe you a question
What happens when you have a low current 12v switch that is off- and the open leg has 12v currently on it and you turn it on?
From reverse activated 12v>>>>> switch <<<<<12v from truck
Do the pixies go up stream like a spawning fish? NO.

I do believe it would be acceptably wired correctly, since the trailer plug will be fused as well.

Please, for the record tell the class what happens when you use Terminal 87a on a standard 5 pin Bosch style relay? What would happen if you had power there and the control side was collapsed? I can answer it for you if you'd like.
Nothing.



Next argument- "I think the sky is blue"

I don't even understand your reply. What the hell are you talking about. First you say wire it up to both sources without a relay and now you are asking how a relay works? Are you seriously a mechanic, or are you just messing with everyone?

Let me break this down as simple as possible for you.

Option A (your suggestion)
Run a 12V hot lead from the reverse lights (either taillight or trailer plug)
Run a second 12V hot lead from the up fitter switch
Tie both into the positive side of the S2
Ground the negative appropriately (I assume at this point, but there's no telling with you)

Option B (my suggestion -also supported by anyone who knows anything about 12VDC)
Run a 12V hot lead from the reverse lights (either taillight or trailer plug)
Tie that to pin 87a on the relay
Run a second 12V hot lead from the up fitter switch
Tie that into pin 86 on the relay
Run a 12V fused hot lead from the battery
Tie that into pin 87 on the relay
Tie S2 positive into pin 30 on the relay
Ground the S2 negative and pin 85 on the relay appropriately

Since you don't seem to understand relays:
Pins 85(-) and 86(+)power an electromagnet.
The opens the switch when 12VDC+ is applied to pin 86(+).
It closes the switch when 12VDC+ is removed.
In the closed position 12VDC+ (if present because the truck is in reverse) can flow between pin 87 and pin 30 (powering the S2)
In the open position 12VDC+ (from the fused power source) can flow between pin 87a and pin 30 (powering the S2)



Now, please tell me why your solution is the correct one (even though it disregards basic 12VDC circuitry logic).

 

[halogrinder]

I don't even understand your reply. What the hell are you talking about. First you say wire it up to both sources without a relay and now you are asking how a relay works? Are you seriously a mechanic, or are you just messing with everyone?

Let me break this down as simple as possible for you.

Option A (your suggestion)
Run a 12V hot lead from the reverse lights (either taillight or trailer plug)
Run a second 12V hot lead from the up fitter switch
Tie both into the positive side of the S2
Ground the negative appropriately (I assume at this point, but there's no telling with you)

Option B (my suggestion -also supported by anyone who knows anything about 12VDC)
Run a 12V hot lead from the reverse lights (either taillight or trailer plug)
Tie that to pin 87a on the relay
Run a second 12V hot lead from the up fitter switch
Tie that into pin 86 on the relay
Run a 12V fused hot lead from the battery
Tie that into pin 87 on the relay
Tie S2 positive into pin 30 on the relay
Ground the S2 negative and pin 85 on the relay appropriately

Since you don't seem to understand relays:
Pins 85(-) and 86(+)power an electromagnet.
The opens the switch when 12VDC+ is applied to pin 86(+).
It closes the switch when 12VDC+ is removed.
In the closed position 12VDC+ (if present because the truck is in reverse) can flow between pin 87 and pin 30 (powering the S2)
In the open position 12VDC+ (from the fused power source) can flow between pin 87a and pin 30 (powering the S2)



Now, please tell me why your solution is the correct one (even though it disregards basic 12VDC circuitry logic).

I'm sorry you can't understand simple logic of what happens when an open circuit has power on it, and you (additionally) add power to the (already powered) circuit. Perhaps you need it in a more internet-troll like communication form? IDK.

I said it was an acceptable way to wire in additional back up lights, based on the circuit load and what it's intended use is- when it's in reverse.
If you wanted to override it with an switch, either way will do it, just run power from the aux to the reverse pin on the trailer hitch. Flip the switch.
I'd be interested to see if the reverse on the tails and the trailer hitch are spliced to separate in the first place. Not sure on that unless I look at a schematic or pin them and check continuity.

Or, you can do a relay set up if you have a heavy load and want to use it as a control rather than a load signal from the aux switch as both you and I have suggested.
You're a feisty one. Simmer down. We're saying the same thing but you like to argue more than my wife.

 

[Jake17]

Simmer down. You argue more than my wife.

crash457...FRF know it all
when in doubt...flips the RETARD switch, like a bitch

 

[crash457]

crash457...FRF know it all
when in doubt...flips the RETARD switch, like a bitch

Nobody here is asking about fake carbon fiber vinyl, Pep Boys graphics, or gaudy Fox stickers. Move along, ******.

 

[Jake17]

nice approach angle

 

[GrdnFrmn]

At the risk of putting my chin out in an otherwise entertaining Internet argument, I offer a third solution that doesn't require a separate relay. Get a two in/one out diode (Roadster makes high power ones suitable for automotive use).

Run a hot lead from whatever upfitter switch you prefer (number 6 on my truck) to one of the diode inputs. Run another hot lead from the trailer 7 pin reverse wire (center wire, I think), or the back up light in the tail light assembly if you prefer. Run a lead from the diode output to the BD S2s. Ground appropriately. Now your S2s will light either from the upfitter or the reverse itself, with no chance of voltage backing up past the diode.

Works great. Credit to Nick at Apollo for the diode suggestion.