I have a 74 TR6 that a previous owner installed an A type OD. The A type OD uses a relay. There is no OD relay in my car and although the existing OD wiring works it is not wired the same as the A type OD wiring diagram shows. Rather than rewire (the existing wiring works) I am looking at just incorporating a relay into the existing wiring. I have attached a drawing of what I believe to be the correct wiring for both A and J type overdrives as well as a drawing of my existing wiring. It looks like the previous owner wired my A type overdrive the same as you would a J type. My question is how do I install a relay into my existing wiring? I think this is the same as asking how would I install a relay into a J type overdrive.