My current headlights are Sylvania H6054 XV 35/65

All fuses Good
Tried all new light (No Change)
Both High Beams work
Turn signals work, markers work, high/beam on off clicks and indicates high beam correctly
Voltage to all three prongs good.

HELP

 

Make sure the contacts for the low beam in the left side headlight plug are clean and making good contact with the bulb prongs. If they are sprung so they don't make good firm contact, they won't light the bulb. Why are you running only 35 watt low beams? Try a set of Silverstars.

 

As I understand it the 1997 + XJs have separate left and right headlamp fuses. The 1993 model year does not. You have checked all the fuses and they are good anyways. I looked at a diagram or two of the 1993 XJ related to the headlamps, and I had just a little trouble understanding some of how it all works. I think I figured it out for the most part? I could be a little off from being 100% though?

It seems with your Jeeps set-up it sounds like you have power and everything is proper up to where it branches off going further to both the left and right side headlamps, since one side works correctly. This means you have a problem from between this point and the effected headlamp. It is probably either a break in the wire or a fault with the connector (corrosion or retracted pin) on the harness side causing an open. It could be too high of resistance in the wire? Or, possibly it could be the result of having a very poor ground connection as well too? I believe both side headlamps each have their own dedicated ground wire to chassis connections (at least they should). Those are all likely reasons... Keep in mind it is still possible the new headlamp bulb could have a faulty low beam filament even though it is new. I think you said you checked the connector immediately behind at the headlamp and found it not to have any power there though. As long as you tested it correctly the bulb is probably okay.

Hook up a multimeter to DC Volts, and turn the lights on. Probe the connector at each terminal with the positive lead, but using the battery negative post for your ground lead. See if you have 12V. If you do, your ground is bad.

If you do not have 12V, turn the headlights off, and probe the connector again, but this time with the positive lead on the battery positive terminal, and the negative lead checking the pins on the connector. If you have 12V, your power source is bad.

If the power source is bad, you will need to check the wiring from the bulb back to where it joins with the opposite side headlight wiring, looking for breaks as the wiring goes back.

If the ground is bad, check the wiring from the headlight connector to the ground source. It should be located right by or near to the headlamp.

If you wanted, you could set the multimeter on the Ohms setting to check for continuity on the ground and the power source wires too. Checking for continuity may help you to narrow things down when tracing the wires backwards to where they branch off going to the left and right sides.

My guess is the problem is due to having corrosion and/or pin damage at some point mid-harness.. at a connection or connector.