I have a 2014 F150 Ecoboost 4x4. When i activate the 4x4 it engages but automatically in the diff lock mode (even though i didn't select diff lock). I've replace the switching mechanism with no success. So i can go from 2WD to 4WD and back again, but when in 4x4 it auto engages the Diff lock but only shows 4x4 on my dash. When i pull the 4WD **** out to 'engage' diff lock it'll show on my dash and when i push it in the diff lock light turns off but does not actually disengage. Has anyone had this issue?

 

You say that pulling the diff lock switch engages it, but when you push it back in, it doesn't disengage? Is this the behaviour in 4x2 as well?

 

Pulling the out the 4WD mechanism in and out engages the diff lock 'light' on the dash, when you push it in the light disappears but the diff lock is still on.

4wd and Diff Lock disengages when i turn off 4x4, so functions as it should in 4x2.

It does not auto disengage over 25mph

Fuses are good

In addition i also had the switch replaced, hoping for a cheap fix and it didn't work.

 

Has it always done this? has anyone worked underneath near the electrical plug on the diff for the locker?


Also, please confirm the following:
1) Diff lock and diff lock light all function normally in 4x2?
2) Diff lock is auto-engaged in 4x4, but no light appears? (how are you confirming the diff is actually locked?)
3) Do you hear the locker at any time?

 

I noticed it about 6 months after i bought the truck, to my knowledge no one during that time has worked near the electrical plug.

answer: 1) Diff Lock and Diff lock light all function normally in 4x2
Answer: 2) When i turn on 4x4 it auto engages diff lock as well but no light appears. I know its on when i go around a corner and the back starts to skip.
answer: 3) no noises are made in 4x2 or 4x4. I even brought all 4 wheels off the ground and crawled under while a friend switched it from 4x2 to 4x4.

PS: added a few more bits of info in my post above.

 

Did it start 6 months after purchasing? or you only noticed 6 months after purchasing and it could have been doing it the whole time you owned it?

Is 4x4 itself *actually* working when you did the 4-wheel-up test?

Does the auto-disengage (locker) work when in 4x2?

 

This isn't a good method to confirm that your axle is actually locked, since all trucks with a part time transfer case will skip and hop if you turn a tight corner on firmer surfaces with 4X4 engaged, axle locked or not. Since the rear end is usually lighter, it'll generally be one of those tires that will eventually hop and skip to release any bind in the system, usually the tire on the inside of a turn.

I'm not saying this is what's happening here, but let's rule out the simple things first.

 

I'm hoping as the OP did a 4-wheel-up check, that they correctly confirmed this operation. But yes, if not, then they need to confirm the 'skipping' whilst in 4x2 with the locker engaged as being the same type, though frankly, i barely need to turn my wheel with the locker on before it's abundantly clear they're locked

 

It must be ruled out! A locked axle in 2WD can feel very much like an unlocked axle with 4WD engaged to those that may not be familiar with binding when turning a tight corner on firm surfaces!

 

I know that i didn't know what the binding should/shouldn't feel like when i was testing mine for the first time - it didn't help that the 4x4 binding on the 2 speed TOD cases is far less harsh due to it being a clutch instead of gears. Hopefully the OP did confirm when it was all jacked up.