I just put a A518 in my 79 Warlock with the 2 pin connector non lockup convertor. Was a little chore but got it going , I wired a toggle switch to blue wire hot and orange etc wire to ground . I have no overdrive , have checked hot wire using pin ground on frame ground and it’s all good . Trans feels firm and solid , bought it out of junkyard with 65,000 miles out of a church van . Going to service and replace overdrive solenoid but I am not sure if this will cure it . Any trans guys out there that can give me some ideas , I see a lot of people put switch on ground instead of hot but I have read people do it both ways . Thanks