Originally Posted by NoGaBiker

You want to be on the “downstream” side of the OEM light, otherwise it will be switched as well. So strip the black outer sheath, exposing the red and black wires that run to the new light. Take a good 3” of that outer sheath off so you have plenty of room to work with.

fish two 15” pieces of jumper wire down from the hole you just cut in the little panel to come out the hole the OEM light sits in. Strip all 4 ends.

Now snip the recently-exposed red wire going to the light, leaving two ends which you will strip. Connect the lower end of each of the jumper wires to one of the ends of the red wires, doesn’t matter which. You just effectively made the red wire long enough to reach up to the switch location. For connections I just used small wire nuts, taped hell out of them for insulation and mechanical strain relief. Fancy people will use more sophisticated methods. I leave that to your discretion

Take the two upper ends of jumper wires which are sticking out of your newly drilled hole and either a) wire-nut them to the pigtail wires that came with our switch, or eliminate those pigtails and crimp appropriate sliding connectors onto the ends of jumper wires if you have them.

Tape everything up nicely, insert switch into hole, insert OEM light back into hole, after testing to make sure it all works.

Originally Posted by GrouseK9

@NoGaBiker nailed it. In a moment of complete stupidity (not uncommon with me) I put the switch on BOTH wires running to the new light. When I figured out what went wrong I had a grand laugh and now another "dumb 'stuff' I've done" story. Pro tip: Follow EXACTLY what @NoGaBiker wrote and do it to the RED line only and that is on the new light only.

Oh, and I'm one of the 'fancy people' which is in direct conflict with my typical dumb-arsed, red-necked core. Once you buy heat shrink connectors you will ALWAYS look for a use for them. I never do electrical connections without them. When I worked on my 1964 Series IIa, I used electrical tape and wire nuts. It led to a lot of "mysterious" problems that took a while to track down. I figure the L663 has enough of those on its own without my contributions. Around the time of my '94 Defender I started to change. Either way works great, but as you can tell from the above story - I have a lot of "user errors" and heat shrink makes them less likely.

Originally Posted by drcoop

Nice job, you'll love the utility of the switch! Eventually when I commit to a dual battery setup, I'll hot wire this great light directly to avoid the obligatory "time out".

Originally Posted by Husky44

Question for the lectrical gurus: would a rotary dimmer switch work without any issues? I'm thinking yes, but I like to ask because I assume that pretty much anyone walking upright with opposable thumbs is smarter than me when it comes to electricity.