Fog lights relay is activating backwards

LJDC

LJDC

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My factory fog lights now go ON when the headlights are OFF and they go OFF when I flip the headlights on.

I also notice that the brights will not stay on—meaning when I pull the lever, they go on momentarily (while I hold the lever) but don’t “click” on. Flipping the brights ON (and holding the lever) will also turn the fog lights OFF.

Background:
I was recently playing with the relay and put some shrink tubing on the #1 pin, so I could keep the brights and fog lights on at the same time. I ended up taking it off, because it didn’t do much anyway. I did all of this when I installed new KC LED fog lights.

But when I look at the relays in the fuse box now, it appears that the receptacle for the #5 pin isn’t there. Might I have knocked it out of the way? Is there a trick to lifting off the yellow tray to get underneath to check?

For now, I’ve pulled the relay so they don’t stay on and run the battery down.
 
It sounds like you may have reversed the wiring on your fog light relay, causing it to activate backwards. This may have happened when you were working with the Shrink tubing on the number 1 pin.

Additionally, the issue with your brights may also be related to the wiring on the fog light relay, as it seems that the two are linked and turning on the Brights may be switching off the fog lights.

Regarding your question about the missing receptacle for #5 pin, you can lift off the yellow tray in the fuse box by inserting a small flathead screwdriver into the small slot located on the tray and lifting it out carefully.

To fix the problem, you will need to properly rewire the fog light relay to ensure that it activates correctly when the headlights are turned on, and that the brights and fog lights are not conflicting with each other.

You should start by double-checking all of the wiring connections to the relay, making sure that they are properly connected and in the correct position. If you have any doubts, refer to a wiring diagram for your specific Jeep model.

Once you have double-checked the wiring, you can test the operation of the fog lights and the brights to see if the issue has been resolved. If not, you may need to replace the relay or seek the advice of a professional mechanic who can help troubleshoot the problem further.
 
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ChatGPT said:
It sounds like you may have reversed the wiring on your fog light relay, causing it to activate backwards. This may have happened when you were working with the Shrink tubing on the number 1 pin.

Additionally, the issue with your brights may also be related to the wiring on the fog light relay, as it seems that the two are linked and turning on the Brights may be switching off the fog lights.

Regarding your question about the missing receptacle for #5 pin, you can lift off the yellow tray in the fuse box by inserting a small flathead screwdriver into the small slot located on the tray and lifting it out carefully.

To fix the problem, you will need to properly rewire the fog light relay to ensure that it activates correctly when the headlights are turned on, and that the brights and fog lights are not conflicting with each other.

You should start by double-checking all of the wiring connections to the relay, making sure that they are properly connected and in the correct position. If you have any doubts, refer to a wiring diagram for your specific Jeep model.

Once you have double-checked the wiring, you can test the operation of the fog lights and the brights to see if the issue has been resolved. If not, you may need to replace the relay or seek the advice of a professional mechanic who can help troubleshoot the problem further.
Click to expand...

Okay, now I want to know how accurate this response is.
 
Chris said:
Okay, now I want to know how accurate this response is.
Click to expand...
Essentially it's correct with a bad narrative. Reversing the wiring won't cause that problem but moving one of the contact wires below the relay socket to the other contact side of the relay will cause that.

If one of the wires was moved from the N/O (normally open) connection to the N/C connection (normally closed) that would cause the fog light to be on until the fog lights were turned on by their switch which would shut them off.

This is essentially what the fog light relay looks like inside...

Capture.png
 
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OldBuzzard said:
@Chris will ChatGPT look at a person's profile to determine year, tranny, etc?

@LJDC are you using the original relays? I've seen a few with different pinouts, which could switch the NO and NC contacts, as @Jerry Bransford showed.
Click to expand...
If it fits the socket inside the PDC it has a standard Bosch pin layout so that wouldn't happen by installing a different relay.
 
OldBuzzard said:
@Chris will ChatGPT look at a person's profile to determine year, tranny, etc?

@LJDC are you using the original relays? I've seen a few with different pinouts, which could switch the NO and NC contacts, as @Jerry Bransford showed.
Click to expand...

I am not entirely sure about that. That’s one of those things where I am wondering if I can train it to do so.
 
I’m using the original relay. I can’t have misfired anything, but I could have pushed a contact over.

When I peer down to the contacts (through the yellow tray), I cannot see a contact for pin #5. Is that what you were thinking of, @Jerry Bransford ?
 
LJDC said:
I’m using the original relay. I can’t have misfired anything, but I could have pushed a contact over.

When I peer down to the contacts (through the yellow tray), I cannot see a contact for pin #5. Is that what you were thinking of, @Jerry Bransford ?
Click to expand...
This is the Bosch pin layout and how it looks from underneath...
Bosch relay.jpg


Bosch Relay1.JPG
 
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Jerry Bransford said:
This is the Bosch pin layout and how it looks from underneath...
View attachment 424246

View attachment 424247
Click to expand...

Hmmm…. that’s not what my relay looks like. Not that it matters, but the pins are numbered 1-5. I can’t take another photo right this second, but here it is when I was messing with the pins—the red shrink tubing is no longer there, and that’s not the receptacle that I can’t see:

IMG_0348.jpeg
 
LJDC said:
Right! Except the part where the fog lights are on when the headlights are off, and the reverse. Hmmm
Click to expand...

I'd have to put more thought in to it, but that relay only does one thing.
Cuts power to fog lights when high beams have power.

The relay mod I use is replacing the relay with a short jumper (pin 3 to pin 5).
That allows the fog lights to have power whenever they're turned on.
 
LJDC said:
Right! Except the part where the fog lights are on when the headlights are off, and the reverse. Hmmm
Click to expand...

I will suggest that your switch is to blame here.
The MultiSwitch on these vehicles is prone to failure. Part of this is because the size of the contacts in the switch assembly are too small for the current they draw.
Over time, they get corroded, worn, etc and become unreliable.
There is a plastic ramp that actuates the connection when the end of the TS arm is rotated. This also wears out.

Either replace the entire MS assembly, or dig out the wires for the fog lights and power up a fresh switch and relay.

Our fogs stayed on all the time due to this type of failure, and I wired in a new switch on the dash.
 
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