Hi all, trying to finish up the rear harness in Dads 67 FB. When replacing the rear pass side courtesy lamp harness I also removed the rear defrost motor. The feed wire on this thing is LONG. Well over 4' of wire, and that is just when laying the "excess" out from mount hole. I believe the "route " the wire takes is up pass side, under the dash and obviously over to dash switch on drivers side. My factory schematics show it as possibly a "20w resistance cable". Can I shorten this wire? In my mind there us no need for 4' of the extra. I would like to trim 3' off, BUT dont want to alter the functionality of the resistance cable.....long winded sorry...