I thought this was going to be an easy fix. I've been searching and found people with the same symptoms and narrowed it down to the switch, and it wasn't that. after that didn't work, I pulled out the millimeter and found 12v power at all the headlights with switch and key off, I don't think that's right; right (it's not switched ground is it)? the 2 prong lights have 12v on 1 wire and the 3 prong have 12v on 2 of the wires. I also have power at the center prong on the relay socket. obviously I have a cross connection somewhere but when I follow the wires from the relay they go to other systems in the truck, all the wiring is stock, what the ****!

 

Yep, headlight switch provides ground path. If the high beams work, but the lows don't, and the bulbs are good, chances are the multifunction switch is your issue. Take the covers off the column, and see if any wires have pulled out. If not, check and see if you are actually getting continuity to ground on the appropriate wire for the low beams. (my guess is, you aren't.)

 

well I just installed a brand new switch yesterday. the fogs now work, but no low beams,; and for hi beams I have to hold the toggle in (they won't stay on). wires in my PDC don't match any on the switch harness. anyone have a wiring diagram or wire color code? I have 12v power on three of the "quad beam relay" sockets. that doesn't seem right. is there an easy way to put a jumper on the headlights?

 

Grab the 01 service manual from the FAQ section. (in the service manual thread) Wiring diagrams are in there.

 

SO, I was getting power where I thought there shouldn't because.... the head lights run on reverse polarity! the switch, switches' ground, not power! so once I figured that out and did some investigating on the service manual, I found it to be the blinker multifunction switch. I bought a new one and now I have light!

 

Think I mentioned that this morning.

Glad ya got if fixed. I LIKE being able to see where I am going...... less exciting that way. (most of the time.)