2014 F150 XL with 5.0L & 6 Speed auto with SelectShift manual mode; I just discovered SelectShift isn't working. When I pull the gearshift selector into the "M" position, the current gear is displayed, but I can't shift it up or down with the + / - selector switch. Pushing the + or - side of the switch does absolutely nothing. The trans stays in whatever gear it was in when the gearshift lever was moved to "M" position and won't shift up or down unless the gearshift lever is moved back to "D", which is how it's supposed to work, but I'm supposed to be able to shift it with the switch.

My first thought is to check the fuse, but I discovered that I don't know which fuse is for the SelectShift power. I can't imagine any electrically powered accessory not being fused, but I don't see a description for the select shift feature in either fuse panel description list.

By the way, the trans performs perfectly normal when in "D"

Anyone know which fuse, and in which of the two fuse panels, protects / powers the SelectShift function?

 

There is no fuse just for the switch. The switch is simply an input to the transmission control logic.

Since the truck is likely still under warranty, take it in (if so) and have it fixed.

 

There's got to be some voltage somewhere. Either + & - on the rocker switch are each dc voltage from the trans and there is a common ground, or the common lead is dc supply and the + & - contacts are sending dc to something at the trans.

 

Not covered by 5yr/60k power train warranty, & 3yr / 36k bumper to bumper warranty is long gone...

 

Found the problem; the previous owner went into the wiring harness that comes down the steering column just behind the dash to pull out a 12v source to run a relay to power a cellular amplifier. The installer was careless and cut an additional wire when the 12v feed wire was cut. The additional wire was the yellow with green stripe which is one of the five wires that runs to the SelectShift connector in the steering column cowl.

A piece of info discovered while troubleshooting; the "+, -" rocker switch on the gear selector lever can be tested with a common VOM for function. I thought it might possibly be a mechanical momentary switch, but it has continuity as long as a button is depressed.