Ok, truck is a 98 with factory single headlight units. Driver side lo and high beams are extremely dim. Almost yellow looking. I switched the bulbs with no change. Added extra ground and still no difference. It only has one fuse in the block under the hood and changed it to no avail. Could the problem be in either the dimmer or headlight switch? Scratching head here and getting tired of not being able to see on my way home from work at night. Any and all suggestions welcome.

 

Yeah pull your headlight switch and check for melted wires/connector/switch.

 

If the switch looks okay , do yourself a favor and get a LMC relay kit for your headlights. IMHO worth every penny.