Hey guys and gals,

Ive been helping my dad track down his transfer case problem on his truck. His truck is a 2001 f250 with a 6 speed manual. He has warn locking hubs, so there is no problems with the hubs locking. This is definately a transfer case related issue.

Right now Im at the point where I wanna throw a toggle in his dash with a fuse behind it, and just jump it so he can turn on the 4x4 high, but I really dont wanna fix his truck like that and give him any bad ideas haha.

Ok so when you go to engage his 4x4 in his truck, nothing happens. No light on the dash, nothing. My dad was a little foggy to me with some details. I believe he said his abs light was on for awhile today, and Im pretty sure he told me that his high idle doesnt work now(he never specified if it quit working the same time his transfer case quit engaging or not). He told me that his transfer case was shifting good, then just quit, no signs other then it just wouldnt work.

Things we have done-
Checked the fuses, all good. (checked both under the dash, and under the hood fuses. I pulled each one out and checked them)

His switch tests fine, swapped switch's with my truck, no difference. His switch works in my truck, so his switch is good.

He bought a brand new transfer case motor, so that part works.

We tested the wiring from the switch to the GEM to the relay holders under the hood, then from the relay holders to the transfer case, and all the wiring from the GEM to the transfer case is good. Wiring from the switch to the GEM is good. (tested continuity tests through all the wiring)

Tested the relays and swapped them, the relays are good and work perfect.

Figured it had to be the GEM then. Got my dad to get a brand new one. Replaced the GEM, so the GEM is brand spanking new, still no transfer case engaging. (d'oh, felt bad about that one, might have to make that one up to him yet)

So this is where Im kinda stuck for now. I have downloaded the wiring diagram (1999 4wd esof.pdf), and have followed and tested almost every wire I can.

Need a little direction or input if anyone has any. The bad part is my dad lives 2.5 hours away, so I cant just go check this or that, but I am hoping to get a bunch of input for the next time he comes out and i can get things working for him!


If anyone has any ideas or input at all, I would appreciate it.

 

Are you sure the shift motor is working? Mines a manual shift, so I can't even describe what it looks like, but I would think you could pull it out, flip the switch, and see if it works...

 

The motor is brand new, my uncle (whos is a heavy duty mechanic) tested it, I personally havent, but Im taking his word for it!

 

Just something simple that came to mind, so I thought I would ask. If the power is getting there, and then motor works, then I suspect something in the transfer case itself. It's weird that it would work, and then not work, with no real warning though.

 

Thats the thing, right now as it sits, the power doesnt get down to the transfer case. There is no sound, no movement when we switched the switch on the dash, like there is with my truck.

I traced everything to the GEM, which we replaced, and still no worky.

So Im guessing I am going to have to start checking things up to the GEM.

I have been reading about this all night, and looks like some trucks had a 4x4 module up behind the glove box, something I didnt know, or check either.

Looking for more input still. And I have been reading this as well...
https://docs.google.com/file/d/0B1up...mM1/edit?pli=1

 

just a guess here but, i think you could still get continuity to check out, with a chaffed wire touching somewhere that could be grounding it out. you may want to take a closer look at the wiring where it could come in contact with something along its route. good luck .

 

Thanks for the post. When I traced the wires, I triple checked the harness, and any points where the wire came close to any possible problem.

I figured since I was digging around looking, might as well do it really well!

So all the wires I have tested, also had no visible damage at all.

 

why don't you just put a manual shift T-case in and be done with that ESOF garbage?





























yea, i know. SHUT UP TOM. YOU ARE NOT HELPING.

 

Haha Well it might come down to installing a different transfer case yet, as my father and I both hate the idea of it being controlled electronically. Where this idea has become an industry standard is just silly for us guys that want reliability, AND keep our trucks for lots of miles.

I mean this is just a electrical system, and should be able to be repaired. But it seems like we have looked at and replaced all the big ticket items.

 

Bump for a magical miracle fix that someone can tell me!

 

I see no reference to checking/double checking the connectors for this system. Given the environment "up there" where you live (mud/water), that fact that you've tested all the wiring, it would seem that somethings screwy with a connector. Pin not making contact, bent, plugged with something, etc, etc.

Shot in the dark and maybe you've already done thing but thought I'd throw it out since you made no mention of connectors.

 

I know you checked the fuses but did you ever check if you where getting power to the switch?

you need to seperate the two sides of the system at this point, find out if the relay is firing and the t case is not responding or if the relay is not firing which would indicate a control circut problem.

 

Thanks for the replies.

Every connector that we pulled apart and tested, was cleaned with contact cleaner and put back together.

As for power to the switch, when I tested that, I tested my truck at the same time and got the same readings.

 

did you check the finnagin pin regulator?

how about the olson coaxial monitor cable?

you may also have a defective flux capacitor.


























yea, yea, i know, SHUT UP TOM. you ain't helping!!!

 

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