I have been plagued by a passenger side headlight out. Changed the bulb to no avail. If the high beams are activated, both work fine. Everything else works (i.e. foglights, parking lights etc.). Anybody out there experience the same problem? I am kinda over driving with my foglights and driver side headlight......just waiting to get a "fix it ticket" lol

 

Sounds like this could be a bad connection inside the socket. Suggest taking a multimeter and with the lights on, check for voltage between the appropriate wires and also to ground. Try cleaning the connections inside the socket and maybe even trying to bend the contacts to make a harder connection to the light bulb. Spray inside the socket with contact cleaner.
Also use the multimeter to verify that both the new and old light bulbs are good..
Let us know what fixed the problem.

 

So I took my rig in to service brakes........and happened to mention that my trailer light receptacle was not lighting my running lights, even though my tail lights were working. Happens to be that the malfunction is related to the above headlight issue. Was remedied by a simple bypass wire however, I am trying to find out if anybody in the forum knows the proper name of the module responsible for the lighting. From my understanding, it is not cheap

 

I have the same headlight issue.