Where are the electricians

Today I went to put in my switch with a relay and was planning to do a Negative Trigger, however, I didn't have a diode so I just wired it as a positive trigger. It works great but I'm looking at the wiring and if I do wire a negative trigger what the heck do I do with the 12v Positive red wire on the switch? The switch diagram says to attach it to 12v Positive but that doesn't seem right to me for a negative circuit. If I can follow the lines correctly when the switch is in the off position then the red wire would feed in 12v to the switch and back into pin 85 which would be bad since pin 85 and 86 are connected. Am I wrong?



Since I didn't have a diode (required per the switch diagram) I just wired it Positive Trigger in this configuration



It works as I would expect but I'm still suck on that red wire for the negative trigger circuit.

 

You need to connect it to ground.

The green and red are the “switched” circuit - with the switch ON you are connecting the green to red to allow current to pass the rest of the way to ground. With it off, you are breaking the circuit.

The blue and black are lighting up the LED. Nothing else. So the way you have the first diagram drawn, the relay coil will never actually complete a circuit and energize.

The Diode is needed depending on how you are tapping your circuit and what you are using for a source and a load - in order to eliminate the potential of back-feeding power through the energized circuit to the source. An example would be when wiring reverse lights - if you TAP the reverse signal circuit to provide the signal to the relay and also have a switch I’m there, run have potential of feeding power to the reverse signal when not in reverse, which causes the shifter light to change and the ECU to potentially do other bad things. A diode would ensure power doesn’t go “upstream” in that circuit.

 

Thank you, now that makes sense to me. I didn't realize the black wire was only for grounding the blue wire and I assumed it was the ground for the dash light as well as the switch. Now knowing the Red and Green are what makes the circuit it make sense to connect the red switch wire to ground. Now if I do that I don't see any need for a diode because there is no power to feed back. Is that correct?

Now I see it like this minus the diode

 

I prefer to draw a relay with this symbol, because it better represents what is happening inside


85 and 86 are 3 and 4 on this picture - there are the trigger coil. 30 and 87 are 1 and 2 here because there are the full load switch.

use a similar symbol for your switch where red and green run through the switch part of the symbol and black and blue are running through an LED separately. The truth is there’s also a connection between the load side of your switch and the black in the switch that lights up the second LED when your switch is “on” but that just complicated things a bit more.

 

Good information. I think I understand everything. I figured there were some internals controlling the light source inside the switch so when the button is pressed one of the lights (top) comes on as well. I'm a software engineer and not an electrical engineer. If this was written in code I'd understand it better

 

Yes.
The one thing to consider is that you may need to switch the red and green wires because of the function of the second “ON” LED (assuming you’ve got a CH4x4 or AOB switch). The “on” LED is connected between one leg of the switch and the ground (black) and it only turns on when the switch circuit is energized. If you have that led on the “hot” side of the switch in a negative circuit, then you will be dumping power through that LED all the time.

 

I’m on my phone so can’t really sketch it ATM, but hopefully that makes sense.

and I’m just a construction guy with a structural background.

 

Ok I agree with that. I do have a AOB switch. So this second "ON" LED, is it getting it's power from the pin 85? I'm thinking if that diode was in there it would restrict the power and not light up the LED ?

 

Well your structural background has this electrical stuff down good. I can usually figure it out but don't want to take any chances messing my truck up.

 

My final laymen drawing is this, realizing that the switch Red/Green may have to be swapped depending on the switch.