Just got a quarter pounder and notice it is 3 wire. Has a black and white cable, and a shorter black cable also. Is the short black cable to ground the bridge? I can't find anything on google and most of the photos I see look like only 2 leads? Also read some rubbish about if you match it with a Fender pick up it may be out of phase and you need to cut a solder jumper wire and reverse the leads white to ground? I have a SD Vintage in the front and I wired both pick ups white to hot on the respective switch terminals. Why would you cut the little jumper wire on the back of the pick up?