2002 F-150 XL Left headlight is out with no fuses blown, I put in a new bulb, tested the contacts on the plug, no power. Low light will not work, high beam works.

I read about the multifunction switch, would that cause the only one headlight to not function?

 

The low beams are spliced togather.
If one side works then it's the splice or the lead from the splice is open.
The splice should be close to the top of drivers side radiator apron.
Take the top cover off to see the harness area and follow the lead from the lamp socket.

 

Which fuses did you check ?

Do the high beams work ( test of ground at bulb connector the quick way ) ?

The reason I ask, is there are 4 fuses in all to check, and each low beam has a separate fuse, they are not a single common fuse like the high beam.

Ref page 210 in your owners manual :
Battery Junction Box Fuse #3 30 A : Feeds the MFS ( and a few other things )
Central Junction Box Fuse #16 20A is both high beams ( and a few other things )

Central Junction Box Fuse #26 10 A is the Right side low beam
Central Junction Box Fuse #28 10 A is the Left side low beam.

With the right side functioning, it is save to say that BJB #3 is good.

When you tested the plug for power, did you check using the ground in the connector itself, or another ground ?
This can also be tested by trying the high beams ( uses the same ground point ).

If you used the connector ground for ref ( or did not try the high beams ), it could be a ground problem, or a blown fuse in CJB Fuse position #28.
Start with the fuse #28