Im in the design stages for a top drive truck to use for hunting. I have solutions for locating secondary controls for everything up top but a control switch for SOTF 4 wheel drive. I’d like to keep the existing switch in the cab and have a switch up top that controls it as well as a switch for 2WD Low. Please let me know if anyone has done this before or even seen it done so that I know it’s possible. Truck will be around a 2015 gas.
Thanks,
Brandon

 

Very cool but your gonna have one hell of a time with the computer and all the sensors

 

Why wouldn’t you be able to splice in before the switch and make an extra long harness and have two switches? Just a thought im no expert.

 

I’m hoping it’s that simple, I’ve just started researching it and I might just have to attempt it. I spoke with a friend that’s a mechanic and he said I might need to put a couple of diodes in the circuit. Hoping to find someone here that has done it before.

 

I have a feeling you will be the first one to do/try this.

Looks interesting

A shop that customizes trucks might be able to assist to at least with ideas even if they haven’t actually done it.

I’m no electrician, but similar to the idea posted above, is it possible to have two switches with their own wiring share the termination point (where the switch wires actually gets attached to the transfer case motor)? Or would that cause some sort of electrical backfeed.

 

From my understanding that’s where the diodes would come into play, preventing backfeed. I need to find a wiring diagram for that circuit and see where everything goes.

 

Maybe this will help some....

 

Thats a start. Thanks!

 

Just a thought, but couldn't you put some type of transfer switch in the cab and tie both switches to it? You would only have control from one switch at a time though.

 

Adding a second locker switch is relatively easy - just wire a second switch in parallel. It doesn't even need a blocking-diode because selecting the Locker ties the switch to Ground.

The problem is the 4x4 Select switch. The Transfer Case Logic Module is looking for a specific voltage level coming from the Mode Select Switch. There are resistors hooked up to each switch position - When you select a function - 2-Hi, 4-Hi, or 4-Lo - a different resistor value is put into the circuit. Each resistor causes the stimulus voltage coming out the of the Transfer Case Logic Module to be reduced by a specific amount. The Transfer Case Logic Module is looking for a specific voltage coming back to it to decide on what mode to shift to. If you do not give it the proper voltage, odds are the Transfer Case would be confused and may not work at all, and/or throw fault codes.

To add a 4x4 Switch to your top-deck - you're going to have to get one with the same resistors to be able to provide the proper voltages back to the Transfer Case Logic Module. Unfortunately, you just can't hook two 4x4 Select switches together. If you did, the resistors from both switches would be electrically tied together. The resistors would be "in-Parallel" and this would send the wrong control voltages to the Transfer Case Logic Module.

To do this correctly, you need to get an A/B switch that electrically isolates the two Mode Select switches from one another. A two-pole relay would work fine. You could hook the two "CCF13" wires from your two switches to either side of the relay. If you have Up-Fitter Switches you could use one of them to control the relay coil. You could set it up so that if the Up-fitter Switch is OFF - you have 4x4 control in the truck's cab, and when the Switch is ON, it sends your 4x4 control up to your top deck,

It's do-able. It's just gotta be done correctly or 4x4 select won't function correctly. It's probably easiest to do if you buy anther Ford 4x4 Select switch module with the proper resistors already installed. The biggest problems would be to tap into the Transfer Case Logic Module harness, and find a spot to mount the relay A/B switch and wire it up..
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