I'll check the highbeam voltage this afternoon. I don't have a regular lightbulb to test with. I've tried several different bulbs, even the known good one from the passenger side.

So something else I should have mentioned from the start, the headlight toggle switch does nothing. I'm not sure what it's supposed to do, but any position I set it to makes no difference. The head lights turn on using the sensor. Not sure if this has anything to do with my problem, but felt I should mention it.

 

If I understand You well, Your xenon driver plug goes into a standard lightbulb socket. Is that correct? If You plug in a standard bulb with filament instead, You may see it glowing if there's a connectivity problem. Xenon one is not giving much of an info here. It costs peanuts, I suggest You to get one. A filament lightbulb has tons of use in troubleshooting.

I don't have my lamp sensor's driven, so I cannot say much in that topic.

 

The cheapest bulb I can find is $13, hardly peanuts . But at this point it's a worthy investment, next time I head out I'll pick one up. This old Blazer has made me good friends with the counter workers at the local parts shop.

I tested the highbeams with some strange results. I put the negative probe on the negative battery terminal and the positive back-probed into the non-working drivers side purple and got 0.8 volts with highbeams turned on and 1.1 on the passenger side.

I switch the probes around with the positive probe on positive terminal, then I put the negative back-probed into the green wire of each highbeam. When turned on I got 11.5 volts on the non-working drivers side and ~0.80 on the working passenger side. I'm not sure what to make of those results. Maybe I screwed up? I still have my doubts on the accuracy of my harbor frieght meter so I'm being careful to test multiple times.


After more pondering, I want to lean towards a bad ground. The turn signal on that side does the "fast blink" like when you would have a light out. Neither light is out. It has done that since I bought it (when that headlight worked). I just assumed the previous owner put a lower wattage/LED bulb in one of the sockets.

 

Hey Danny,
Sorry for late reply. I've been to busy to keep up with BF.
A picture worth a thousand word:

I am hoping it's all clear now There is a sensor switch implemented somehow, that is not mentioned on the schematic. Your readings You're posted are leading to a blown fuse - You have two separated ones for either side. But due to a "green" color I've decided to better make a sketch. Aging of pigments on the wire coating may be misleading.
Unknown things are with "?". On a left side voltmeters show You how to make a measurement and yellow lines tell You what action to take. Hope it's clear enough. I am an engineer not a painter

 

I've got some googling to do to figure out how to read a schematic.

I was searching around to find any info I could about this issue. I started playing around with the multifunction switch (That's the turn indicator/cruise control/brights switch right?). I tried holding it when I switch the brights on to see what kind of results I would get. Nothing too interesting there. I decided to hold it again on the "turn off" click. The passenger side headlight would turn on, but the drivers side wouldn't do the flickers until I let go of the switch. Not sure how it's normally supposed to behave when doing that, but thought it was interesting. I'm heading out tomorrow to pick up a regular bulb. Hopefully I'll have your schematic figured out by then.

 

Reading schematics in this case resembles a labyrinth puzzle. You have to find the way from a positive battery terminal through a "red wire", relays, lamps, "brown wire" till the negative terminal.

 

Well, I'm not sure what to say now. Mike, if you're ever in my neck of the woods I owe you a steak dinner.



Replaced this 15A fuse for the LTHDLP and she's shining brighter than ever.
It should have been the first thing I checked, just didn't make sense to me for it to be a fuse if I was getting a little spark out of the lights.

And as for only being able to operate the headlights with the daylight sensor, to switch to using the manual switch all I had to do was toggle the dome override button a couple of times.
Also, fixed my drivers side turn signal flashing fast. Turns out I DID have a burnt out bulb in the brake light. The "bright" mode of one of the bulbs had burnt out. I like it when things are quick and easy fixes.

Thanks again, Mike. You were a huge help!

 

I was just helping. You did the job
I am glad to hear. It is always welcome to hear a prompt feedback, especially that the vast of the threads are abandoned.
EDIT:
The electronic drivers may be tricky (as in Your case, for example), so to exclude them at once it is always a good idea to load with the resistive lightbulbs.