Stingray. This is a bit of a long post, with multiple sections.
There is a lot of information and misinformation in our wee forum. You kinda need to decide which is which.
WIRE TAPS
It’s strongly suggested to NOT use wiretaps/scotchloks as they will eventually fail. Instead learn to do a proper wire splice.
BACKUP WIRE ACCESS
Like Smurf I tapped into the taillight harness for a reverse wire.
Here’s a long but good link from 2017 that I used to help me wire my BD reverse lights to both reverse and AUX 1.
https://www.fordraptorforum.com/threads/baja-designs-s2-back-up-lights-install.55707/
TONY CANDELLA
Tony founded and still owns an excellent automotive electric company. See the link below.
I suggest that you buy Tony’s books on automotive wiring. There’s a section on splices in his book. If you need supplies, everything that Tony sells is top quality. Check out the strand count of the larger gauge wires that he uses compared to other wires. I’ve used his 4/0, 2/0 and 6 gauge wires, which are amazingly supple. I digress…here’s the link:
https://ceautoelectricsupply.com/wiring-and-efi-conversion-books/
RELAY & WIRING
I put a Hella waterproof relay for the backup lights up on the passenger side firewall where it will stay pretty dry.
I chose to build instead of buying a harness I figured out how long of wires that I needed, then called Tony up and had him wire me up the Hella relay.
If you do a search using “relay” and my user name, you’ll find some pictures. I’m not a wiring genius, just a good fabricator.
Best of luck with your install!