1999 Peterbilt 379 help on the chicken or marker lights needed

Howdy folks, need a bit of help on a truck my son in-law just purchased. We are getting ready to DTO the truck this next week and we've got everything in order except for the lights that run down the sides of the cab and sleeper. Not needed for the DOT sticker, anyway I don't think so, but we want them working.

Here's where we are at. We do see the white and black coming off of the front light on each side and going up into the cab. From there we think they are going over to a switch in the main panel, but this is where we are getting a bit confused? Below are a few Q's on the subject


#1. We believe White is ground.
#2. We believe black is +12vDC.
#3. I have a switch that is labeled CL Lights? Is this the correct switch? I look at the back of that switch and one side goes to a yellow wire? Which might go to a relay back at the fuse panel? Or, it could go to the white wire? Very confused on this. Hard to see.
#4. The other side of the switch goes to a red wire that is spliced to a black.......this makes even less sense.
#5. at the fuse panel, there is a CL lights fuse and relay? I assume these are both somehow involved in the circuit for these lights.

Things I've done so far:
#1. Simply took +12vDC directly from the battery to the black wire at the first light. This did light each light on both sides of the cab and the sleeper = good!
#2. On the drivers side of the inside cab, I found the black and the white behind the panel on the left side of the steering wheel. took the Battery +12vDC directly to the black here and got a big spark and no lights lit??? This is where I stopped tonight as it got to cold (-5 degrees) and dark to continue. Things quit making sense at this point. I will recheck to make sure that this black wire is in fact the one that goes down to the lights.

What I still haven't figured out is what the CL Lights switch would really be doing? Does it simply complete the +12vDC continuity? Or, should it be whit to white to complete the ground? I would figure it would be +12vDC of course, but I'm not seeing the right wires at the switch to do either? Strange

 

Thanks Wore Out, we'll review the toggles and make sure we have em all up. I believe we've tried that, but at this point we'll give it a go again.

 

Good info, I'll crawl back in the thing tomorrow and check the thing out. Maybe take a pic or two also.

 

Ok, I had to run out and look at a few thing. The switches are Headlights, CL Lights, and Aux CL Lights.

The AUX CL lights switch has two red wires on it with both being on one side of the switch. I'm having difficulty traces these two reds, but it looks like one goes to a yellow or white and the other ends up spliced into a black, which makes even less sense.

I'll have to get a better look at these once I get some heat back in the day tomorrow as we are now below zero again.