4WD not working

[MikeC9917]

Thanks in advance for any help you all can give me.

Earlier this year my reverse gear went out while I was parking a pop-up trailer. I had the transmission rebuilt and everything seemed fine until yesterday when I tried to use the 4WD. That was the first time I tried using the 4WD since having the transmission done.

When I turned the switch to A4WD, the indicator on the dash showed that it was on, but when I drove it the 4WD never kicked in. When I tried the 4H setting I got nothing, and when I tried 4L setting, the dash said to put the transmission in neutral, which I did, but nothing ever happened.

Does anyone have an idea of what might be wrong, and could it be related to having the transmission rebuilt?

Thanks again for the time.

 

[jeff kushner]

Not having any idea what year or engine your truck has but to be safe:
Engine running, in Neutral, foot on the brake, then switch it, you should hear a clunk as it engages the front transfer case. If not, I (I'm not an expert Ford mech) would start by making sure all the fuses and relays were ok. Maybe a call to whoever did your tranny work might help? If the trans computer is looking for neutral and it doesn't see it, could be the neutral switch.

jeff

 

[MikeC9917]

OK. I found an awesome post by xjcamaro89 that describes in detail the IWE system. I think I now have at least a rudimentary understanding of how the 4X4 system works. Since I don't have any grinding noises, I'm thinking that the transfer case shift motor is the most likely culprit. Does anyone have any thoughts?

 

[Bedrck47]

Welcome to the Forum.

One of the most important items is to let people know the year, engine and model of your expy. The second most important item is that your thinking but maybe your just guessing.

Being you have IWE's the easiest way to check them is to raise one of the front wheels and with the engine off rotate the wheel and see if the axel turns. Then start the engine and rotate the wheel and see if the axel turns. The axel will turn when the IWE is engaged. (no vacuum) and will not turn when the IWE is disengaged (vacuum applied)
Then do the same for the other side.

You may want to start checking fuses with either a meter or test light Just remember that some fuses have power at all times and some will only have power when the key is in the run or start position

 

[hammerg26]

Check the fuses first - I believe it is 104 (under the hood)...
If that does not work, could be the transfer case shift motor...
Also check to see if the previous owner did anything creative - i.e. disconnected anything.

 

[Bedrck47]

Good information However it doesn't apply to the OP's 2005 expedition as the 05 doesn't have a under the hood fuse box

 

[hammerg26]

My apologies. Did not see that.