this is my problem,have a new teleflex tach set at 6p.Have a new harness that goes from remote control to tach.3 wires,blk/wht/brown.My motor ia a 1971 merc. 650,ser #3155375.the control box on the motor has 4 posts on one side and 3 posts on the other.according to my seloc manual my wiring diaghram is type 3 ignition.the 3 wires on the box have blk/wht/brown from the distributor and one wire from mercury switch. the 4 posts has a blk. from the coil and a ground to the box.it also has a red to one post,a white to one post,a brown from one post.the brown wire comes from or goes to the engine harness then to the external harness straight to the tach connector..In order not to burn up any thing can I disconnect the brown wire on the 4 post side of the control box and splice it to the yellow wire on the rectifier.I don`t believe using the brown on the 3 post side will help get me a signal for the tach.also,should the tach be set on 6p or another setting.emailed teleflex but they were not sure how to wire this motor to the tach.Hope I gave you enough info. to help me out,many thanks-----------------walter.