I'm not sure why the wires would be exposed to the elements, however if you want to seal them, wrapping in electrical tape and tie wraps is definitely not the right solution.

I would utilize heat shrink tubing:

Heat Shrink Tubing http://www.homedepot.ca/wcsstore/HomeDepotCanada/images/catalog/HST-125_4.jpg

Thin wall heat-shrink tubing is great for cable insulation, marking or bundling, with superior mechanical, abrasion and moisture protection

Basically you slip this over the entire connection and then use a heat gun to shrink the tubing tight against the connections. It's a cheap and effective way to protect electrical connections.

I'm not sure why the wires would be exposed to the elements, however if you want to seal them, wrapping in electrical tape and tie wraps is definitely not the right solution.

I would utilize heat shrink tubing:

Thin wall heat-shrink tubing is great for cable insulation, marking or bundling, with superior mechanical, abrasion and moisture protection

Basically you slip this over the entire connection and then use a heat gun to shrink the tubing tight against the connections. It's a cheap and effective way to protect electrical connections.