Hello all. First time poster, long time reader. Thanks for all the great info along the way. I haven't found this exact scenario in any of the forums yet, so I'm tossing it out there. Anyway, after a long road trip, my 99.5 f250 with the 7.3 and esof 4x4, manual tranny, sat for a few days and when I went to start it, it had shifted itself into 4lo and wouldn't shift out no matter what I did (reverse, neutral, shift, stomp on brake and shift, etc). So I pulled the transfer case shift motor off and manually shifted transfer case to 2wd to make it home. Now trying to troubleshoot.
I have read dchamberlain's advice about checking the two prong connector at the motor, and I there's no voltage when I move the switch. I checked the resistance and it registered some, so I assume the circuit is good and therefore the connector and wire is good. I replaced all the relays and checked each socket for good power. I also checked the switch and it has power.
I'm stumped and sick of sliding through the Michigan snow. Anybody run across this issue or have any ideas? Thanks in advance.

 

Was it sitting in Neutral when you shut it down?

Denny

 

Im pretty sure it was in neutral when I left it.

 

Have you exercised the system since this occurred to see if it wasn't just a bump of a beer can? (I'm from the mitten too).

Denny

 

Yeah, I hooked the shift motor back up today with the new relays installed. It didn't budge.

 

Just trying to help. Are you chipped and what kind.

Have you disconnected your batteries and rebooted?

Denny

 

The hubs just locked, or did you go into full 4WD?

 

No, I was in full 4lo for sure.

 

You must have missed it Rich, but he mentioned that it shifted into 4 low and would not come out of 4 low. I have been following this thread a bit because I am interested to see what the problem and fix action are. I have not seen this issue on FTE yet, but I am still a new born considering the age of FTE.

 

Was the 4x4 light on in the instrument cluster? Was the switch still in 2WD? Did the switch move freely or feel bound up at all? When moving the switch, could you feel it stopping at each setting?

 

Yes, the lights were on on the dash and the switch was in 2wd. The switch moved freely to all positions and didn't feel bound up. There was a definite stop at each position.

 

I would start looking for a short in the wiring somewhere that would energize the motor to switch on the 4x4. This doesn't sound like much fun, but if you start at the motor on the transfer case I think it would be easier than starting at the switch. Keep us posted on what you find for others to learn from your experiences.

 

That's one way to put it... but instead, I might say to myself "Read the freaking post ya bum... he took all that trouble to give good details."

I don't have the wiring diagram in front of me right now, but I recall it was a flip-flop arrangement with relays. I want to say if one relay contact failed, the other would reverse the motor (putting the truck in 4 Low) - but I need to refresh my memory with the wiring diagram. The hubs shouldn't lock (I think), that would be a separate circuit.

 

Well thanks for all the ideas. After doing more reading on this, I'm starting to wonder if it's the GEM. My heater core ruptured a year and a half ago and got coolant all over the passenger side under-dash which is where the GEM is located I think. But it was so long ago, and I don't have any other weird gremlins that a bad GEM would cause, so I don't know. The other suspect is the shift motor itself. Could the position sensor be sending bad info to the GEM which is causing it to misbehave?

I'm honestly tempted just to swap to a manual shift transfer case and some warn hubs. Esof just seems too unreliable. Any thoughts on any of this? Thanks again!

 

The GEM is behind the fuse block by your left foot, so the heater core would not have been an issue there. That's not to say a leaking windshield didn't get you.

How are you at reading electrical diagrams? I don't see the GEM involved with ESOF here. I prefer a big mechanical lever for shifting 4X4 - but I really like my auto-locking hubs.