I upgraded the exterior my 2000 XJ limited to LED bulbs recently with these, ordered them off Amazon.

Alla Lighting 3157 LED Bulbs Super Bright 3156 3056 3157KX 4157 3457 4157NAK 3757 T25 Wedge LED

I ordered the Tail light set about 2 months ago, signal/brake/tail and back up bulbs. Installed them and they work great. A couple days ago, I ordered the front/side signal bulbs. Installed them and they work fine with the headlights off(they blink very quickly but I am not bothered by this), but when I turn the headlights on, they light up, but will not blink. Both the hazards and signal lights do this, and it affects the rear signal and hazards as well. Additionally, the green signal indicator arrows on the instrument cluster light up and stay lit when I turn on the headlights. I've done no mods to the wiring aside from cutting and splicing the wires on my third brake light when I installed and LED fixture there last spring.

Anybody else have this issue and if so were you able to correct it?

Any input is appreciated.

Almost forgot, I installed these after the taillight bulbs, but before the front/side signal bulbs mentioned above, with no issues.

New Osram Chips 110W 5x7 Inch Led Headlights 7x6 Led Sealed Beam Headlamp with High Low Beam H6054 6054

 

Replace your stock flasher relay with an electronic flasher relay. I believe it is a Novita EP27 relay. You're probably getting some resistance issues somewhere. On my 95 when I replaced all the exterior bulbs with LEDs I got a weird issue where my brake lights would both flash with the blinker no matter the side. Swapped back to incandecant tail lights and that cured the issue. So could installing some resistors inline with the taillight wiring but to me installing resistors defeats the purpose of putting LEDs in, in the first place.

 

This sounds very familiar.
Go read this:

https://www.cherokeeforum.com/f67/le...000-xj-246749/