I recently hard wired my V1. I found this info helpful to custom wire it. If you only need to hard wire it for power without plans on using the concealer remote display, all you need is any 2 wire phone cord. You don't need the direct wire adapter. The direct wire adapted does not have any voltage regulator circuit in it. Simply connect the phone cable pin #3 from V1 to a ground and #4 to a switched power source from your fuse box with a fuse in-line. If you plan to use the concealed display at some later time, you'll want to use a 4 wire phone cable.