Did some swapping several weeks back and wound up with this Expedition.

When I got it, the 4 wheel drive switch would only bring up "A4WD" and nothing else.

After searching all over, Google finally pointed me to this site and a post that sounded very familiar.

The solution was to disconnect the battery for a while and reconnect. That gets everything working again - including 4L and 4H.

Now my problem is this - I have to re-do the battery disconnect every few days. No actual milage seems to apply - the truck can sit for two or three days and the next time I get in, the switch has no effect. At other times, it may go several days with or without driving before it quits functioning correctly. When working, it appears to work well... But kind of pointless if I have to go through this routine every time I need 4X4 to work.

I have read of a "GEM" unit or some sort that controls the 4X4 function..and some other things. I assume it is the cutting of power that resets this controller.

Some advice, please.

 

Have gone back through and checked fuses, connections, hoses, etc. Still no explanation. Disconnect the battery, reconnect and the switch works and the transfer case engages and the 4X4 works just fine.

 

maybe the battery is shot. but that doesnt sound like it would make sense, it was a suggestion. maybe try leaving a charger on it for a few days and seeing if it acts up.

 

Found answer on another board. Transfer case motor.

$69.99 for reman with lifetime warranty from O'Reilly's.

 

Personally, I would NOT buy reman electronic pieces. I opt to pay blood for them, oem from ford.