So I buy this 03 F-350 with shift on the fly 4WD knowing nothing happens when I turn the 4WD switch. I found the transfer case motor was bad (open), replaced that but still nothing. I measured voltage to the control module at the connector pins and those seems to be ok. Tested selection switch and that seems to be ok. I grounded pins at module to light the 4x4 and Low Range dash lights and they work ok. I tested the transfer case control relays and also was able to click them grounding the module connector pins. I didn't try that test with the new transfer case motor plugged in yet. I didn't want to mess anything up or get it stuck in neutral somehow.

About all that is left is bad control module?

The manual says the two 4x4/Low Range dash lights should come on with the key on as a bulb test? Can anyone confirm that? Mine don't so I assume that points even more to the module?

I just want to make as sure as possible before I drop $300.
Anyone have a good recommendation of where to buy that module?
Thanks,
Larry

 

I have a 2002 F350 4X4 and my 4X4/low light does not come on with the key on

 

Here is what the manual says:

4WD system indicator lights

The 4WD system indicator lights illuminate only under the following
conditions. If these lights illuminate when driving in 2WD, contact your
Ford dealer as soon as possible.

•

•

engaged.

 

The 4X4 does come on when the truck is started for a second I hope this helps