Well did the continuity check like you said. I'm assuming you meant continuity with ground so thats what I checked. But nothing happened in either 4hi or 4lo in either relay position. So maybe I have a bad GEM? Or maybe my research on the gem numbers isnt really for a ESOF system...

 

I can't really say about the GEM. The one you have could be bad or it could be that it just doesn't support the 4x4 functions. I looked on the service DVD that I have and it doesn't list part numbers.

The only suggestion I can make is to talk to the parts department and see if they can tell you if there are different GEM module part numbers for 4WD and 2WD. You could also go to www.partsguyed.com and send Ed a message. He's pretty handy with parts.

 

I talked to my local parts dept. and they gave me a part number of f81b-14b205-ep. I've read in a few different places that those part numbers are the newest replacements for 14b205-GB part that is currently in my truck. I'll probly give them a call back tomorrow and see if they can tell me what my part number is made for and if it will support 4wd.

 

well, done tons of more research and removed and reinstalled my gem a few times... Finally got some decent wiring diagrams and went to poking wires and connectors... I've found this much... when i ground out my relay the tcase motor works but the dash light still doesnt come on. checked from the gem connector to relays and switch. all good wiring. i'll check from tcase to gem to see if i've got continuity there.. So still tossing around ideas that maybe this gem isnt a 4x4 gem and maybe the gem has to be programmed from the dealer... contrary to my local dealerships belief. so yup... thats the update...

 

Something occurred to me this morning, so I went and checked. I've attached the Removal and Installation procedure from the Service Manual for the GEM module in your truck. The first lines reads like this.

Now this only specifically mentions tire size and axle ratio, and doesn't say anything about switching 4WD functions on or off. But it DOES prove at the very least that the GEM does need configuring. The method has probably changed since this manual was written, this is off of a 2007 version DVD that covers many makes and models of Fords.

I kinda wish one of the smart dealer tech's that hang around in the forum would see this and respond.

 

Unrelated question, but you have a 4X4 swith on the dash in a 99? Mine doesnt not a few others I have seen.



Just curious
Bryan

 

yea i've read that on a few different forums i've come across. I'll probly call a different dealership to see what they have to say. I know that my truck has a recall on something to do with the speed sensor... maybe if I bring it in for that recall they'll have to reflash the GEM... At least to try and save a little cash.

Yes. Its a turn style switch that is really similar to the headlight switch. Its in the dash just to the left of the radio.

 

Strange on the 4x switch. Mine is the old style on the floor. Rather have that anyways. One less thing to break. You must have later model 99.
Thanx.

 

yea if I had my choice i'd have the ole stick on the floor... buut beggers can't be choosers..

 

Lol. I hear that. Hope ya get your prob figured out.