Yes that's with the bulbs unplugged and probing in the bulb socket

 

Im thinking bad headlight switch

 

I finally had time to get a new headlight switch put in and that wasnt the problem. I think i might change out the dimmer switch if that could be the problem?

 

You have constant power on the ground wire. That ain't right.......

 

Update on my driver side low beam problem. I swapped out the multifunction switch and still have the same problem. After cleaning up the wires for the headlamp sockets I noticed I certainly do not have a black ground wire. On the driver side I have a red/orange, violet/white, and a solid violet wire. On the passenger side I have red/orange, violet/white and violet/red. After looking at the 2000 manual those are the same color wires I have except my violet/white is in the middle where in the manual it is on the outside. It shows the solid purple wire in the middle in the manual. So do i have wiring for a 2000?

 

Also is there any fuses or relays I'm missing besides the two 15amp fuses in the pdc

 

Do you have daytime running lights?

 

No daytime running lights. I do have fog lights although I dont think that matters

 

Ok, your headlamps get constant power via two fuses, both in the PDC. Fuse "B" is for the right side, fuse "C" is for the left side. There should ALWAYS be power at both headlamps. (assuming the fuses are good....)

From there, the Violet/white wires (from both sides) go to joint connector 1, in the PDC, and from there to the beam select switch. So, since one side works, and the other side does not, your issue is probably between the headlamp, and the PDC. With the headlights on low beam, check and see if the violet/white wire on the 'problem' side, see if you have a good path to ground. (both headlights disconnected.)

 

That's what I'm thinking the confusion is coming from. If I'm not mistaken 98 had a pull switch for the lights and 99 has the three position twist **** with the instrument panel dimmer next to it. Your wire colors also match the 2001 manual I'm looking at. VT on the left side and VT/RD on the right side should always have power, and that looks to be the case although it's mislabeled black in the table above. The headlight switch sits *after* the light bulbs and connects the bulbs to ground which is very different from the 98 and earlier where the switch turns on power to the bulbs.

Looking at the table my first hunch is a wrong bulb, or maybe a defective one. Double check you really have 9004 bulbs not the very similar looking 9007 style. Then, remove the bulbs on both sides and plug the "good" one into either side. If it works correctly in both sides the other bulb is the problem. If not, use an ohm meter and measure resistance to ground (still both bulbs removed) on the RD/OR and VT/WT wires for the different headlight settings. It should read open with the headlight switch off, close to zero on the VT/WT with low beams and close to zero on RD/OR with high beams.