I made it independent of the transmission for several reasons. Some people will want to use an 833 4 speed, some a 727/904, some a 500/518, others may even go with a tremec. I wanted it universal. Secondly, Chrysler really dropped the ball and made overdrive a pushbutton actuated decision. Keeping the factory trans controls means you at least have to run an on/off toggle switch to turn OD on and off, but the computer would at least control lockup. The pressure switch control that PATC offers is far superior to any other method, especially at $85. put it in drive and everything is automatic....lockup and OD, the way mopar should've done it in the first place.
So, my options were to leave it like the factory wired it and leave the buyer to have to wire in a toggle switch for OD anyway, or to leave it to the buyer to decide whether they wanted to wire in a toggle switch or a pressure switch. It seemed an easy decision to me, particularly knowing that the majority of guys would likely be running the 727's and 904's their cars already have in them. Not everyone wants to do floorpan surgery to put a 518 in their car, particularly A-body guys
Finally, this harness setup will work with every transmission except the 46RE (1996+ 518's) or their weaker equivalent the 42RE, as those transmissions have to be controlled by the JTEC 96+ computer
