A headlight harness will help a lot. H4 conversion housing like the ones made by Hella (I have the e-code) will be amazing.

I highly recommend against getting cheap flea-bay junk like those Cree lights. Spend the money on quality parts for your own safety and others on the road.

If you want a decent upgrade, start with replacing the stock harness to one with relays. I used this Putco harness (though I'm sure there are better ones). I saw a significant increase in brightness with the stock bulbs. Just something to consider.

The best bang for the buck is to upgrade your wire harness. The way the factory wiring is routed on your XJ, the power goes into the switch in the cabin of the vehicle only to go out into the engine bay and supply power to your lights. Even a very small drop in voltage at the headlights themselves will make them appear dim. The way to get the lights brighter is to feed them more power. There are kits online you can buy or you can make one yourself using a write up like this: http://go.jeep-xj.info/HowtoHeadlightLoom.htm

If you don't want to make one, you can use the harness that everyone seems to buy on Amazon. A lot of people who have reviewed the product are talking about putting them into XJs. http://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4G

The way a headlight harness upgrade works is it uses relays. You don't remove any of your existing wiring, just add the kit to your existing electrical system. Instead of your factory wiring feeding power to the lights, it now activates relays which will draw power right off of your battery. That delivers more power to your lights and makes them brighter without even replacing them.

Many people will recommend upgrading the headlights themselves, but be aware that the vast majority of the kits for sale online aren't DOT approved. That means you will fail a safety inspection if your state requires them and you can get a ticket for having them on your vehicle when driving on the road. The DOT regulations are to keep lights from blinding other drivers by defining cut off points of the beam and specifying focused beam patterns. If a cop pulls you over for suspected non-compliant headlights, all he has to do is look at them. If the glass doesn't say DOT, you're getting a ticket.

An alternative that a lot of people get away with are using E-code headlights. Autopal and Hella make lights that are compliant to European standards, but they're still not DOT approved for use here in the United States. People seem to get away with them though because at a glance they don't look like the cheapie "for offroad use only" H6054 composite housings for sale all over eBay. The Autopal and Hella headlight housings allow the user to pop in H4 headlight bulbs. That opens you up to a whole lot more options in terms of lighting. Fitting HIDs in an XJ can be done, but simply popping a cheap HID kit into a H6054 composite housing isn't going to do the trick because an HID bulb is longer and will project light in a very different pattern which can blind other drivers.

There are also LED H6054 headlights on the market as well as true HIDs for H6054s. They're expensive, but they exist if you want to spend the money. Truck-lite makes LED headlights and they're $215 each. The "boobie light" Real factory-made and DOT approved HIDs (not some enclosures a guy on a forum made in his garage) cost a grand a pair including ballasts. They're the Philips Bi-Xenon XP6054. A guy on jeepforum has/had them, but that's a ton of money for a pair of headlights. This link shows pictures from that jeepforum user. http://www.headlightrevolution.com/Starr_HID_5x7_Headlights_Black_p/starr-xp6054b.htm

My .02 worth for ya..... Go in this order instead of jumping right into a set of LED headlamps.

1 - Upgrade the wiring harness.

I installed a Putco harness in 2013 when I first got the XJ and it was a definitely improvement.
Putco 230004HW Premium Automotive Lighting H4 100W Heavy Duty Wiring Harness and Relay

Other folks have gone the eBay route, and I bought one of these on a whim (because it was stupid cheap) just to see if the quality was worth it.
CERAMIC H4 HEADLIGHT RELAY WIRING HARNESS 2 HEADLAMP LIGHT BULB SOCKET PLUGS 7

Ended up not installing it because I had other things to work on instead of replacing the Putco harness that was working fine. Overall though, the quality was surprisingly good and I would have used it if I didn't already have the Putco harness.

For all the negative comments people have about the Putco upgrade harness, it's still working fine a little over 3yrs later. Knock on wood, of course.

2 - Get a set of H4 housings. I bought these off Amazon, but there are other reputable brands out there which work just fine.

GENSSI DOT H6054 7x6 Inch 200mm Headlights Pair with Bulbs Non-Sealed H6014/H6052/H6054

These came with some crappy OCONUS-made no-name bulbs that sucked balls and were immediately thrown in the garbage.

I went to my local PepBoys and grabbed a set of Sylvania SilverStar "Ultra Halogen" H4 bulbs and threw those in the housings.

Holy shit, #1 & #2 were an incredible upgrade to the shit stock XJ headlights.

If you're looking to stay right at or a hair under $100 that's the way to go.

Last year, I came into some $$$ and got it into my head that I wanted LED headlights. Went this route: Truck-Lite (27450C) Headlamp

Wow.

Significant difference from the H4 bulbs + wiring harness upgrade but I'm honestly glad I did the H4 bulbs + wiring harness upgrade first.

Now that said... In hindsight, the LEDs weren't absolutely necessary and I could have put the $$$ into a SYE or something else.

But hey, ya learn as ya go. Right?

Non-mobile: http://www.amazon.com/dp/B001P29X4G/ref=redir_mdp_mobile/184-6657873-1060049

^That's ^why ^I'm ^here, ^I ^don't ^judge ^you. ^PM ^/u/xl0 ^if ^I'm ^causing ^any ^trouble. ^WUT?

It's hard to beat the Chinese at this one... I've seen a guy on Facebook reselling prebuilt harnesses as his own creation, but I'm more interested in making a quality product that's going to outlast the rig it's installed on. I want my reputation to be built on quality and value for the dollar.

Example:

For $20:

http://www.ebay.com/itm/CERAMIC-H4-HEADLIGHT-RELAY-WIRING-HARNESS-2-HEADLAMP-LIGHT-BULB-SOCKET-PLUGS-7-/330997592807

For $40:

https://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4G/?tag=vig-20

And at the premium/benchmark end:

http://www.lowrangeoffroad.com/ipf-wiring-harness.html

If I could make and sell a harness that people would be interested in, I'd be game. We'd be talking OEM quality TXL wire, ceramic plugs, HELLA style relays... but it's not going to be $20. That's the hard part, being competitive in price and quality in relation to other offerings.

$83.94 IPF housings
$20.98 Hella H4 55/100W
$27.34 Putco harness
$14.56 Backup relays

$146.82 for a sharp cutoff and much more light on the road, and an incredible high beam, delivered in two days if you have an Amazon Prime membership. I bet you use high beams a lot now, but you'll probably rarely feel the need to use them on the road with this setup.

$147.99 for a 50 inch light bar. Even though the headlights offer a lot of light, having extra flood would be great when off road. I don't actually have this yet, but I plan on buying it as a reward for getting some work done on my XJ. Mine is still new to me, and I haven't yet had the time to earn it yet.

Less than $300 and two days for an incredible amount of light output.

If I don't buy that light bar, it's because I'm getting a Cree light bar with XP/XT or XM emitters that I'll be upgrading...I'm on the hunt for a light bar that uses XTE emitters like this light because output can greatly be increased by swapping in XP-L's, and more than doubled if power can be increased. That mod is more of a hobbyist thing than an attempt to save money, and not all of them would be done anyway since it'd sacrifice some throw for flood.

https://www.amazon.com/dp/B001P29X4G/ref=cm_sw_r_awd_RsQDub1QPR7JG

That's the exact harness I bought.

The thing that sucks about Cherokee headlights IS the wiring.

Buy this and install it.

http://www.amazon.com/gp/aw/d/B001P29X4G/ref=redir_mdp_mobile/184-6657873-1060049

Changing the lights themselves will not help without feeding them ample current.

Stock lights work GREAT after you fix the wiring.

It says it doesn't fit, but it does. Trust me, I'm a stranger on the internet.

Unfortunately if you are on a paved road, its illegal to have auxiliary lights turned on (unless its a private road). Have you considered upgrading to an H4 harness on your lights with relays?

http://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4GGGGG
Also, how old are the current headlights? Over time, bulbs get dim. If they are really old, you may just need new lights

This would be the better option, wouldn't it? It converts it from 9004 to H4 safely?

https://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4G

Good to hear. Did you make a harness or buy one? This one? - http://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4G

I got the Hella housings that take an H4 bulb, then put SilverStars in them because I like the nice white color temperature.

I think the biggest difference honestly came from this harness. With it bypassing the stock wiring (if I remember correctly it just uses the stock light cables to trip the relays) it can supply a lot more juice from the battery.

I have the 55/60 watt bulbs now, but I might swap in the 90/100's when these go since the harness can support them.

I had a similar issue with my XJ. Electronically there is no other form of resistance on the wire when off then the switch and over time it can wear out just like any other component. I installed this wiring harness that added relays to the circuit. not only does it brighten up your headlights but it removes the load from your switch. Its a really simple install, the hardest part is taking off the grill.

If anything a harness won't hurt. I upgraded to the Hella e-codes and versus stock wiring there was a noticeable increase in light output.

https://www.amazon.com/Putco-230004HW-Premium-Automotive-Lighting/dp/B001P29X4G