Cut and install heat shrink over one end, offset your wire splices, solder together, small section of tape over each splice, then wrap with the foil that is in cable and you can use a small piece of tin foil, slid up and shrink heat shrink tubing, then coat with liquid electrical tape. Once that is cured wrap with electrical tape. Be completely water tight. Have a couple I have fixed that have run completely submerged in water with no problem.