Okay so i have had to do this on 3 trucks a 1993,1992, and a 1998. It stresses me to death everytime but i found with a little thinking and paitence there is a much easier cost and time effective trick. All 2002 and older cummins have a headlight point switch. There are about 9 spade connections. In most of all headlight switch failures is caused from the switch going bad causing a short which then makes heat and melts the plastic. Your first though is shux! Most people will say okay go snip a wiring harness off a scrap truck and order a new switch. By the time thats all done you 50$ in and all kinds of butt connectors. After some thought and really looking at things. The wiring harness that all your headlight leads and your mains run to which is a black plastic piece that has 5 blue wires with are your direct wires to the light and you have your 4 green wires which are your constants. Usualy the failure or melting spot is around one of the directs. Instead of replacing the whole pony tail if you look closely the black plastic piece is just a holder and orgaizer for all the wires that have female spade ends on them so its very easy to switch your light switches. On top of the pony tail is a white piece that holds the female spades on all the wires in there set whole. If you pop the piece out which is easy just take a flat head screwdriver and work your way around and it just pops out. Once that is off you can see a little better view of the female spades. Now the only thing holding your female spades in is a little clip inside each hole that you cant see. The most organized way to do this is is to pop one wire out at a time and plug it into the new switch. Note (IF ANY FEMALE SPADE TERMINALS ARE DAMAGED FROM HEAT NO NEED TO WORRY JUST GET A NEW CONNECTER AND CRIMP IT ON) . Now once you have the switches by eachother and ready start with your blue wires. Just take a flat head screw driver and push from bottom and the wires with the spades perfectly intact will pop out. Then just plug it right into your new switch. Repeat that process one by one until they are all done. Now that you have all your wires reconnected it should work just fine. Also another good thing is if you do have another wire melt maybe cause of your gauge lights are hooked to it or what not. It wont melt the switch at all . It just melets the very tip of the wire. Mean you just get your switch out and just crimp a new female spade and bam your back in buisness.Here are some photos to help visualize.On the left of the picture is the wiring harness that is damaged with the white piece still on. These pictures are from my 1998 but its all the same down to the first gens.