New to me 2001 4.7L and the four wheel drive doesn't work. NV233 and none of the lights in the switch work either. I checked the feed wire to the switch and it's getting power from the fuse. Would this be the switch or the module? And where in the factory manual is there troubleshooting this system? All I see is the mechanical repairs.

 

Check fuse A in the PDC, it feeds the TCCM.

The LED's are fed from fuse 11 in the JB. They are switched by the TCCM (grounds switched).

The manuals are very poor when it comes to diagnosing electrical issues. They tend to focus on mechanical problems.

 

If you can't hear or feel the transfer case shifting, I'd say the issue is your control module, TCCM. They are a little tougher to find online these days, but they are there.

As for replacing yours... just get ready for some bloody knuckles. It's located behind the kick plate below the steering column, then on the right side of that. Else, remove the dash. Many, like me, did it without removing the dash, hence, bloody knuckles.

Check out this thread for troubleshooting and replacing the TCCM.

Good luck!

 

Man is everyone having this same problem lately? Lol. Check the connector on the top of of your transfer case. Mine broke a clip and it wasn't seating good.

 

I got the module out in a half hour. The biggest problem is the wiring harness is too short to pull it forward enough to remove the connectors. Ordered two used modules just for backup for $60 shipped.

 

Good luck!

 

Got the modules and both work so I got a good spare or a tested one to put on Ebay.