I noticed my low beam was out, so of course I go and get the best I can find. I start to replace it and I notice that the old light looks good and the high beam works fine as well. I put the new one in and sure enough the low beam is not working still. I checked the fuse for the low beam passenger side and it is good as well. Any ideas?

 

It is a 2001 F-250

 

check for good contact in the socket, if you do have good contact, take a multi meter and check for a good ground, you most likely have a good ground since the high beam works. I would bet its an open in the low beam circut, cant tell ya where cause it can happen at any point along the wire. I would check at connectors, but ya gotta look close, and dont fail to back probe connectors. Good luck

 

A "light duty" or a "Super-Duty" F250? The circuits are similar but different.

 

It is a super duty. I checked the to make sure all the contacts were touching, so i think it must be a broken wire somewhere.

 

Verify BJB fuse F23 is good.

Verify you didn't get a bad bulb. Swap it with the other side.

Verify power is at the supply side of F23 when the low beams are activated.

Check for continuity between the load side of F23 to the low beam connection at the socket.

One of those circuits will be open.