RE: here
Not to be funny, but the pad, oil pan heaters are in every parts house here. You only need one of about 100 watts for you pan. We put them on auto trannys here, too. If your using all of them (battery pad as wel), we install a weather proof electrical duplex box inside somewhere in an inconspicitious spot & rund a 12 guage cord out through the grill.
On that freezplug heater you installed......, put some diaelectric grease on the terminals now while it is still clean. Otherwise the terminals will get dirty from road grime/salt, etc., and the next thing those little terminals will burn off!
There is a 1500 watt freeze plug heater in my 8V92TT and it will heat and start the engine in the coldest applications. That is in conjunction with oil pan pad heaters.
Forgive my spelling
Lee in Alaska