So I upgraded my headlight harness, the one Ksuspension sells. Everyone is like "It's plug and play, no modifications needed!", I should have known better. My 97 has the factory fog lights, which messes with the upgrade. To mitigate any problems, I rewired the fog lights fully through a separate relay and switch with all new wiring. The mod is actually really similar to the headlight harness mod, except with a new switch. the switch controls a relay connected directly to the battery and fog lights. I assumed this would fix the problem where high beams get stuck on, however I still had to wire the fog light relay wire from the old headlight harness into the new high beam wire to fix this. So the high beams now go on when you push the turn signal switch away from you. The issue still present is when you pull it toward you, like just to flash your high beams, it still turns the headlights off fully? I can no longer just flash my high beams by pulling in on the turn signal switch. Is this just an accepted flaw of the head light upgrade? I don't understand why it would work like this if the high beams are usable by pushing outward. I am looking for a fix, or at least a way to trouble shoot, help is appreciated

UPDATE:
It's crazy, my the actual flasher mechanism on my turn signal switch just happened to break right around when I was doing the headlight harness upgrade. I replaced the switch and it fixed it. What bad luck

 

mine has relays and flashes, so it must be possible, check the FSM wiring diagram to see if there is two separate outputs from the turn signal cluster (which you would expect)

PO did mine , it has 5 relays and every wire is black, so I havent messed with it, cause it works,

has a separate fuse for high beam which blew a couple of times, which is how I found out about the weird bypass system

 

I added my fog lights to my '00 that did not come with them so when I upgraded the harness this was not an issue.
Could swear the fix for this was listed on the Ksuspension website.

 

There's a simple fix somewhere.

 

I added fog lights to my 2001 xj but I used the factory wiring all I had to do is add the relay to the under hood fuse box and added to the wiring because the factory only ran the wiring as far as the radiator core support and add in the switch on the inside .I also added a headlight upgrade wiring kit and that was plug and play just needed a good ground and a fused power . mine flashes the headlights it works just like the factory setup but now gets full system voltage .

 

The problem described is one normally associated with LED headlights, not the loom upgrade.

I've fitted several of these harnesses to various vehicles, including 2 XJ's with factory fogs, & never had a problem. Then again, neither of those XJ's had fogs that went out with hi-beam, as they're supposed to, for reasons I've never understood.

 

It's crazy, my the actual mechanism on my turn signal switch just happened to break right around when I was doing the headlight harness upgrade. I replaced the switch and it fixed it. What bad luck.

 

Well that was unlucky, but glad you've got it sorted.

 

For anyone looking for the fix here was the thread I came across and bookmarked when I get to my harness....Fog light harness upgrade

 

I'm curious to try that, as my foglights have never worked as the factory intended (& UK law requires), which meant I didn't have any (additional) problem when I fitted the relay harness.

Nope, only one red wire - but, curiously, when I looked at the remains of my '96, which never had fogs, that does have 2 red wires.