Originally Posted by dusterbd
helping a friend of mine convert his 75 chevy truck from a 4 speed to a th400. i know that there is some sort of electrical setup for the trans kickdown.
what is the easiest/most economical solution for this? these trucks just about dont exist in salvage yards in my area, so i cant just go snag stuff from the junkyard. thanks guys. michael
Hey Michael, there is a 12v terminal on the driver's side of the transmission case. When you apply 12v to it, the transmission downshifts from 3rd gear to 2nd gear.
The OEM arrangement had a switch under the accelerator pedal. Anyone who has that arrangement for sale thinks they are made of gold, so I would try to rig up an aftermarket switch that would work off the throttle linkage, such as this offering from B&M.....
You should have a vacuum line from the intake manifold to the modulator and a 12v wire from the switch to the kick-down solenoid spade on the side of the transmission case. Take 12v from the ignition switch, run to the switch, then out of the switch to the spade on the trans case.