Hey Bob. I bought the lamp from Dime City Cycles online. Search "old school Headlamps" on their site. The headlamp was around 60 bucks. I then agonized about how I was going to go about this. I didn't want to run it off the bike battery and I wasn't sure I could. The bulb that it comes with is incandescent and is 12 Volt 36 Watts. Either way I wanted to power it independent of the bike. I looked at videos on Youtube but there aren't a lot of things tackling this specific application. A local Hobby shop recommended swapping out the original bulb for an LED, which I originally resisted but after thinking about it for a while and getting nowhere fast, I decided to do just that.
At Walmart I purchased a 250 Lumen Headlight that people wear on the heads, I think it's made by Coleman. 20 bucks and it runs off of 3 AA batteries. That solved the power problem completely but created some new ones. I like to hobby so I have a lot of patience. I was trying to rig a remote on/off switch and that may be possible for someone who knows electronics better than me but I couldn't whip that one. My workaround was to drill a pinky sized hole in the top of the headlamp housing so I can reach in and press the tiny button on the circuit board that supports the LED light. Not perfect but it works. To turn it off I pull a battery, which interrupts the circuit. That much took the better part of a Saturday, painstaking work with delicate little parts and stuff. I thought that was going to be the hard part. I didn't realize I was going to have to customize the mount as well.
Sunday... The mounting bolt on the headlamp is around 3/4 of an inch thick made to securely mount it to a motorcycle. The hole on the front fork is around 1/4 inch, large enough to support the piddly stock headlight. I didn't think it would be a good idea to substantially weaken the fork by drilling a huge hole through it. I love this bike so I don't want to harm it or myself. I removed the 3/4 inch bolt which left me with 2 brackets that held it. I fashioned a piece of wood large enough to fit between the brackets and I used some 10 Gauge wire fit through a small hole I drilled in the wood to marry the two. I then proceeded to carefully drill a hole, front to back, through the wood that would accommodate the factory bolt that came with the Yukon. At some point, I plan to swap out the wood piece for a piece of hard plastic of the same size. Probably over the winter. Lastly I mounted the stock headlight on an accessory 8 inch handlebar that I got on Amazon. All this took the better part of Sunday. I now love the way this looks and I am glad you asked.