I have had a dim passenger headlight since I bought my Cherokee a couple of years back, but I just got a garage, so I decided to actually try and fix it. The issue is not the headlight itself because I could swap the driver side and passenger side and the passenger was still dim. Today I tried taking off the back cover of the plug to check for corrosion and it did look like there was a some. I tried taking a flat head and cleaning off some of the corrosion that way (probably a bad idea, but hindsight is 20/20), and then I put everything back together. Now my passenger headlight doesn't work at all. I checked with my multi-meter and there no continuity.

Sooo..... where do I go from here? Is there a way to pull the wires out of the plug and clean them? This is my daily driver and I would really like to get it fixed so I can drive at night again. Any help is appreciated.

 

Simply splice in a new plug, then install an upgrade harness and be done with it. You'd be totally amazed at the difference! The upgrade harness takes power directly from the battery, not thru the headlight switch.

 

So just cut off the old plug and solder the new one? I don't actually need the upgrade harness right? I may get the upgrade at some point, but I am just looking for a quick fix ATM. What exactly is the point of the upgrade harness? Just to avoid potential future problems that may be caused by the headlight switch? And how much does this upgrade harness usually cost?

 

$30 for a plug-n-play harness from Amazon. By not running the current through the headlight switch and undersized wiring, you'll full voltage and brighter headlights. Also a good idea if you decent to upgrade to brighter headlights.

Or just replace the plugs and switch to LED headlights that draw less current.

 

The stock headlight setup in the XJ frankly sucks. It's the same design used in 1950s-1960s cars where the substantial current required to operate the headlights is handled directly by the headlight switch and the long wiring runs that lead into it. The relatively high resistance makes for dimmer lights and the heavy current makes for short switch life.

The upgrade harness uses the headlight switch as a trigger for relays that handle the heavy current to the lights using a direct run from the battery. Headlights are much brighter even with stock halogens and the headlight switch will last much longer since it only handles a small amount of current.

You do need the upgrade harness.

https://www.ebay.com/itm/330997592807

 

My 37 Dodge had that old system AND a 6-volt system. I might as well have had 2 kerosene lanterns hanging on the front! I used a truck relay and they were much better.