I have a 1998 Dodge Ram 1500 Sport. When I have my headlights on
bright they sometimes flicker off leaving just the fog lights
working. When I put them back on dim they work fine. I tried turning
off the fog lights and turning the headlights on bright but it did the
same thing. I replaced the headlight switch with a used one over a
year ago. I am wondering if it might be the turn signal lever that is
bad. Any help would be appreciated.

With the headlamps on, you will have voltage on the lg/bk wire going
into cavity 21 on the dimmer switch. <multifunction switch> If you
have voltage there, you're headlamp switch is ok.

The wire for the dim headlamps is the vt/wt wire coming out of cavity
18. The rd/or wire out of cavity 20 is the high beams.

Hope this helps

Denny

I just re-read your post. Your fog lamps shouldn't be on when your
high beams are on unless somebody has modified the wiring.

No, my fog lamps are not on when the high beams are. It is when the
beams are on high the head lamps go out leaving the fog lamps on only,
unless I have them turned off.

Not sure if this is applicable for the 1998 model, but some of these
problems were blamed on cracking dashes which push on the wiring. I
have a 2000 model and was affected by it. Now reading you post, I
recall having had similar behavior intermittently with my headlights
to the extend that it went completely dark. My dash got replaced by
the dealer for free by now over a year ago and I have not had a
problem with the headlights since. Again, not sure if that has
anything to do with, just a thought.