I bought a 2000 Jeep Cherokee and at first the headlights and parking lights worked fine. I only had one cigar outlet so I bought an adapter from Walmart and plugged it in and it worked, then my headlights stopped working. I checked the fuses and the cigar outlet fuse was blown but it was still working. The fuses seem to be fine, I also replaced the relays (bought 2 from napa) and that didn’t fix it. Just replaced the switch and if I barely pull on it then the parking lights light up, but if I bump it they turn off. I have no idea what is going on, any input would be appreciated

 

Park outside? Rodents?

 

if its like my '96, the headlight switch harness is very short and the plug is prone to damage.

Its a very tight fit, and what can happen is the male pins on the plug can get damaged or pushed back in

If jiggling the switch body or harness makes things work, this may be your problem

You need to remove the headlight switch again and examine the plug for any evidence of damage

If there is, you have to individually bypass that wire

Its a very nasty job

 

Check the connections at the headlamp bulb, test with volt meter, confirm the ground pin is also good. On mine the connector at the bulb as bad, the wire corroded inside the connector, and that cause big problems.

If the lighter still works with a blown fuse as you stated, then something is NOT wired correctly. Check and confirm the correct color wires are plugged into correct pins on the fuse panel, assure the correct color wires are on the lighter socket. look for non factory wire splices. Check your schematic to see what else is fused by the lighter fuse and see if that item also works with a blown or missing lighter fuse. the light should NOT work with a blown fuse in its circuit.