Hey Lennox! OK, so what year is this out of? Is the car you are putting it in carb'ed or efi'ed? As most of us know, when the trans goes from 3rd or 4th to OD (tcc engaged), you can expect an rpm drop 200-400rpm. For this to happen, we have to possibly wire in the 4th gear switch and and a switch wired in for the tcc via the brake switch! Why the brake switch? We have to allow the tcc (torque converter clutch) to disengage when the brake pedel is depressed. Other wise it is is like slowing down a manual transmission without shifting out of high gear!!
Hello, the car is a 56 Pontiac and its carburated. The trans is probably a 1990 ish 700R4 from a car. A good man named Paul gave me this info today...........see if this sounds right to you. A switched 12V wire from the toggle switch connects to the outside front post of the plug on the side if he trans. This power wire should extend into the trans and connect to the pos side of the solenoid coil at the front under the filter. The neg wire from the coil goes to the 4th gear port switch, where the blue terminal is connected to the single post, normally open switch. Paul says that this should lock up the converter in 4th gear only. The grounding of the 4th gear gear switch completes the circuit. Sounds like it would work to me, Plus Paul has done this many times, without problems. If anyone can touch upon this issue anymore please chime in!! Thanks.........Lennox.