I've had this issue for a while and only solved it with some sketchy wiring but went back to clean up and am stumped.
I drive a 2001 ranger xlt. When I turn the headlights on the running lights and dims work fine but when I cut on the brights then its completely dark except the running lights. I've checked all the fuses and I cant seem to find the cause and can't find anyone with this specific issue.
thanks in advance

Welcome to the forum

Most likely culprit is the Multi-function switch, turn signal stalk

Check if you have "flash to pass", pull back on the turn signal stalk and Brights should come on while holding the stalk back
If they do the fuse 24 in Engine Fuse box and fuse 33 in cab fuse box are OK
If not then recheck those 2 fuses
If they test as OK then the mechanical switch inside the Multi-function switch may be bad

When you push the stalk forward to activate the bright lights full time that disconnects the low beams from power, so they should go off
And high beams should come on, if not then mechanical switch inside the Multi-function switch may be bad

Below is the wiring diagram for 2001 head lights

Pull out the multi-function switch and unplug it
Test if the Dark Blue/Orange stripe wire has 12volts, it should have 12volts all the time from fuse 24 in engine bay, not key on/off power or main light switch power

If so then plug the switch back in, and test the Grey/Orange wire while multi-function switch is push forward(brights ON), should have 12volts via the switch, if not replace switch

Thanks for the welcoming

When I pull the stalk back the dims stay on instead of switching to brights. I've tested 24 and 33 but still no luck. Would that still indicate an issue with the switch?

Yes, switch is bad

Just an update. I just replaced the multifunction switch and still no brights. Fuses were checked during the original post so should still be good

Are you sure the headlight bulbs are any good ?

Yes they should be, I've changed them about 3 times since issue started. Unless I've somehow been getting the wrong bulb then I don't think that's the issue.

Try checking for voltage at the lamp sockets.

I don't have a multi-meter but I took a test light to it. There's only one signal at a time, as marked above. Left gives a signal on dim, middle gives a signal on bright (when they cut off), but no signal from the right. I'll try and get a meter to test it properly but this is what I have for now.

Are you using the correct bulb ? 9007

A 9006 will plug in and do exactly what yours is doing now, low beam will work, but no high beam, they are wired differently.

One connection will be the ground. Are you testing to that connection, or are you testing to the vehicle frame?

I think the issue must have been a mixture between the Switch and the connectors. I replaced the connector on the right side and now its working fine. Thanks for the help everyone.