need some help here I've put in an 85 700r4 into my 86 chevy 1/2 ton that had a turbo 400 in it. the 700r4 came out of a 86 1/2 ton i managed to take the tv cable and wiring out of the truck for the tranny which only had two wires one blue that went to brake switch and a green wire that was just hanging there because the motor was gone already.I've put the tranny in hooked the blue wire to the orange one that was for the 400 in my truck and the vaccum line to the carb and grounded the green one. I'm thinking this can't be right because the torque converter isn't locking in forth so my question is what is the green wire for and sould that vac line be hooked to the carb or intake thanks
05-03-2012 09:56 PM
dont matter about the vacume line check to make sure you dont have any slack in the TV cable At WoT any slack in it and the pressures will be wrong does it shift at low or high RPM?
05-04-2012 01:43 AM
As far as I know the 700 doesn't require any vacuum signals. Also, isn't the T400 an electric kickdown? If so, the wires in your truck probably won't be correct for the lock-up 700. You will have find out how the lock-up is wire inside your transmission and wire the truck and transmission plug accordingly.
05-04-2012 09:10 AM
seems to shift fine and there is no slack in the t.v. cable at wot.when i did take the pan off there is a singal wire that goes to the solenoid so thats a self grounding one. There is only two wires that came in the plug with this tranny one (blue) was for the brake switch it was orange for the t400 as for the green one I did put 12v power to it and now it seems like its locking in third goes to forth not a bad shift and its doing 2300 rpm at 60mph with 4:10 rear, Before when there was no power it was like 2700 rpm. The wires do run through a vaccum switch, this switch should only allow power through when there is enough vaccum, correct so if its letting power through all the time then that switch is nfg, does the 700 only need power to lock up? Maybe i'll put the power on a toggle switch let it get to forth then flick the switch and see if it locks.
05-05-2012 02:45 AM
The 700 only needs 12v and ground to lock up. I don't like using a manual lock up switch. The main reason, if you forget to turn the switch off, the transmission will stay locked up even when you are trying to come to a stop. Could be a dangerous situation. I have mine set up the lock up when the trans shifts into 4th gear, via a pressure switch sensing 4th gear hydraulic pressure. When the pressure switch senses pressure, it closes and ports 12v to ground locking the convertor. I will say I do have the option of manually locking the converter, but I haven't hooked that circuit up yet, and probably won't.