Help I am in need of a 2003 F 250 Gem Module. My issue is that my 4X4 does not work. My light does not come on when I flip the ESOF. Dealership states its the GEM module. I do not hear anything when I shift into 4X4. I put new Wern manual hubs on as well. Could it be something else than the Gem Mod? I am told by Ford that the Gem mod is not available until June.


The part number is 3C3Z14B205AA

My vin # is 1FTNW21P63ED18241

Thanks in advance

 

The super duty's are good for having wiring problems that kill the whole system. I just had to replace a wire from the t'case motor up to the fuse box in my 04 Ex...

I'd imagine that is more likely than a GEM myself, but who knows...

 

I've a problem and hope someone has a clue. A neighbor was charging one of the two batteries on my 99 powerstroke F250. He put the + clip of the charger on the neg. battery post, and - clip of the charger on the positive post.
The radio of the truck, which was parked and off came on. He felt the charger may have been on backwards for a moment or two. He did a test to see the draw down on the battery while parked and determined it was in the .65 range and believed he may have damaged the radio and it initially intended to replace it. He continued his testing with the cables off the batteries to see if the charger was damaged. He continued testing and noted that charging the batteries when connected created a different outcome. He then felt the alternator may have been damaged. His last test involved removing the fuse to the radio and conducted a charge test, then a draw down while parked and the range was in the .5 level and after 40 minutes or so came down to the .2 level. He feels that the GEM was likely damaged but only for the 'radio' wire. He tried installing a diode in the radio wire but that did not correct the draw down. He proposes to disconnect the wire in the GEM and connect the radio wiring to a different source of power. He feels this will salvage the GEM and not be an issue. The truck is parked for extended periods so charging is necessary and unless he corrects the draw down the batteries won't hold a charge strong enough to start the truck after about 3 days. He's priced some GEMs on Ebay for about $300 and feels he is responsible but doesn't like to pay that much if he can fix it as I've indicated. My suggestion was to take it to an electrical shop and spend the $100 for a test and they should be able to pinpoint what does, or does not need repair or replacement. The only other glitch is that he has read that if you drive the truck for a few miles it may just reset itself and problem resolved. The truck has been stored for 5 months.
My simple question is: Would the 10 amp charger potentially damage the GEM if connected backwards for less than a couple of minutes? I would have thought it might blow a fuse. Anyway...some helpful advice is welcomed. CJones
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When my 4x4 wasn't working the dealer said all test showed I needed a GEM module. Turns out it was the relays instead. Under the hood by the firewall/drivers fender, there are a couple of boxes big enough to hold two relays each. Open the one that is closest to the fender and swap the two relays around see if that makes the 4x4 come on.

 

Hello Jello I will check that out this evening. I finially found a GEM mod used and will get it this week. There are no other symptons that my GEM is bad other than the 4X4 not working. Did you have a light in the dash when your relays were not working? I have no light no nothing. Do you have to buy the relays at the dealership? Thanks

 

I also had no other symptoms of a bad GEM module, and no lights on the dash. The relays you can get at the dealer, and they're not expensive. But swap the two relays before you buy new ones or switch one with the trailer battery charge relay. The relays get moisture in them and stop working.

 

those fuses are for the towing lights from what i understand. so how did that fix your problem?

 

Before you replace the GEM module.... try a system reset.

Sometimes, that also will free up a jammed /sticking relay.

Needless to say, check fuses.


I had to replace some relays on mine --- wear from old age!

 

yes i checked all fuses... is there any relays? that make the 4x4 work also and can you tell me where they are located and which ones? this is driving me wako..

 

Do the system reset first.

GEM modules rarely fail --- if it does fail, most likely it is just corruption of the flash.

 

The little box closest to the drivers fender is only big enough to hold two relays, there are no fuses in there.

 

Ok I'm confused now that box on the driver side next to firewall
Has 3 relays and 2 fuses maybe you have a different model ?
Mine is a 03 f350 6.0 diesel sd
Can you send a pic ?

 

Right behind the power steering resevoir beside the drivers fender.


It's the one on the right

 

gem modules go out more then you think. most common cause is from a leaking windsheild.

 

Ok it looks different what yr is your truck and what motor ?
It's way to cold to get a pic now but in the am I will put 1 on thanks