arokcrwlr

I posted this a few years ago in the "2009-Present Ford F150" sub-forum. I thought I'd post again here to make it easier to find in the future in case anyone is interested in doing the mod.

I performed this mod on my 2010 FX4 and it worked perfectly. I just bought a 2014 FX4 and miss this mod already, so I plan to do it on the new truck as well, so I had to search for the steps again...

Disclaimer: these are the steps for a 2010 FX4 - other years may be slightly different, but shouldn't be substantially so.

Why?

It allows you to disconnect the IWEs while in 4wd. My main objective was to have the option for 2wd low range. Another benefit, if you have an e-locker, is the ability disengage the front hubs and effectively have the e-locker in 2wd to the speed limitation of the 4wd mode selected (not an issue for the 2014 as it allows e-locker in 2wd, but for older models the e-locker only works while in 4wd).

There are many benefits/uses - here are a few:

• Useful in backing a heavy trailer up an incline - easier on the transmission, more control because of the lower gearing, etc.
• It's great when maneuvering into tight places where low range is desired for more control, especially if you need to turn the front wheels full lock - no driveline bind that would occur if in 4wd.
• Any other scenario where you'd want 2wd low range on a high traction surface where 4wd would cause driveline binding.

Here's how it's done...

Refer to the ESOF schematic for your particular model year (I had swapped in a Raptor TCCM in my 2010 - that's why I show a Raptor ESOF sch.). The wire from the solenoid to the TCCM needs to be switched to ground when 4wd is engaged to supply vacuum to the IWE which keeps the hubs disengaged.



Locate the IWE solenoid on the driver's side in the engine bay - it's next to the vacuum booster.



Per the schematic, constant power is provided by the GY-RD wire and the BN-BU connects to the TCCM and is the wire that needs to be cut.



I used a 30 amp relay to do the switching to help with trouble shooting and make it easier to correct a faulty switch in the cab. I mounted the relay to one of the vacuum booster mounting bolts and used a relay pigtail for the connections.



Then it's just a matter of making the appropriate relay connections and wiring the switch in the cab - all wire splices were soldered and covered with shrink tubing. Pin 30 connects to BN/BU wire coming from solenoid. Pin 87a connects to BN/BU wire going to TCCM. Pin 86 and 87 go to ground. Pin 85 comes from a switch that has 12v.

With the switch off, the system works as Ford intended. Switch on, grounds the solenoid completing the circuit and keeps vacuum going to the IWEs - i.e. with 4WD selected, flip the switch on and it will unlock the wheel hubs.

All relay ground connections were routed to a ground point on the left side of the engine bay.



Connections cleaned up and routed...



Switch connection poked through the main wiring grommet on firewall...



Power for switch from a fuse piggy back harness...



I tested it at various speeds with/without the e-locker and it works perfectly. Install the switch in a location of your liking.

If anyone decides to do this mod, I hope you find this useful.

arokcrwlr

Any reason why this hasn't been moved after nearly 3 weeks??

Just curious...

arokcrwlr

Make that 4 months... Did I post in the wrong place?

Scott91370

My 2015 has the same color wires.

Had this on my Ram and it sure is nice when moving heavy trailers.

Gypsy

Excellent. Thank you for sharing.

badtziscool

This is an awesome mod! I'm surprised that this thread doesn't have more comments than it does. Good or bad.

Scott91370

Finally got all my switches mounted and did this setup. I didn't pay attention when making my connections and got the wires backwards from above - this caused a Check 4x4 light. Everything worked as it should, just got the light. I swapped the wires to the correct positions and no light.

arokcrwlr - I notice you haven't been on in a while but THANKS!

STingray1300

Wish I has seen this earlier. I will be pulling up the Service Manual to verify wiring for my '13.

Thank you arokcrwlr!

STingray1300

So, I wired this all up on my '13. Got the wrench and a fault on the dash. In the midst of tearing my hair out as to what could possibly be wrong, I decided to investigate the relay's schematic. Low and behold, I found why mine didn't work. The relay.

I use only Bosch relays. Always have. But I didn't realize that there were different internals to theses relays available! (I love learning something new!)

The relays I use on accessories is a "019" series (0 332 019 _ _ _), where both "87" pins are power out connections. The one needed for this project is a "209" series (0 332 209 _ _ _) where the switch cycles the connection between "87" and "87a".

Hopefully this will prevent someone else from having to spend some head-scratching time!

STingray1300

Alls well that ends well... Installed the new "cross connection" relay, and it works awesomely!