Extension Cord connection (Splice Box)

Custom cable connection can be dangerous because of ease of pulling wires out of connections and exposing naked wires.

This splice box makes cable connection strong and safe.
For outdoor extension cords use water protected heat shrink butt connectors, like
https://www.amazon.com/Connectors-Eventronic-Waterproof-Automotive-Electrical/dp/B071L6VDLK/ref=sr_1_7?crid=3JC3KW2GX0DVA&keywords=heat+shrink+butt+connectors+16-14&qid=1575741324&sprefix=heat+shrink+butt+connectors+16%2Caps%2C162&sr=8-7

Connect all wires with butt crimp connectors and shrink insulation with heat gun or flame.

Put connection in one half of splice box and attach with 4" cable ties.
Attach 2nd half of splice box using 2 wire ties.