Checked all fuses and they are good.Parking lights work .High beams only work when I pull high beam lever back.Ex 2003 6.0 limited.Also bulbs checked ok

 

Disconnect the bulbs and check for current at the connector with the Low Beams on to see if they are getting power up there. I know there is a relay to control the power, but I'm not sure where it is located.

 

I had the EXACT same problem as you do (drove me crazy trying to find the problem). Mine was a bad connection in a connector under the steering wheel column cover. Remove the cover and the connector in question was on top of the steering column. This connector goes to the multi-position switch on the column. I can send pics of the area if needed.

 

Power on high beam when lever pulled no power on low beam.Bulbs checked ok .

 

Well guess what .You nailed it.I tilted the steering column a few times and the lights came on.Thanks for the info.I am a happy FTE member.

 

Glad that fixed your problem now get in there and check the connector if you haven't already. Mine didn't have a good connection and was arcing. Could be a potential fire hazard. Better check it just be on the safe side.

 

That's great information! I have to bookmark this one!