i think gem modules numbers must match..

 

There are 1 or 2 electrical boxes near the under hood fuse box that is located on the drivers side inner fender. These boxes control the electric shift on super duties,your problem could be with these boxes.

 

I had Gem module problem just like yours and didnt feel like buying a new one so I just wired the wires from the under hood part as stated above to by-pass the gem module and wired them to a reguar 3 way switch in cab if having another switch in the cab doesnt bother you it only costlike $2 for switch and whatever wireing.

 

You mind going into a lil more detail?

 

JUST out of curiousity-----have you checked the power wire to see if its getting power there at all. And if so how is the ground wire doing--good connection.

Other than that I do believe its in the GEM. BUT you could just run a jumper wire and try (your own "switch") and test the control switch that way.

 

I had problems with the 4WD on my dually right after I bought it. The dealer replaced the GEM, but got a bad one and had to order another one. I know the parts guy and he told me some of the new ones that come in are bad and on top of that, they are getting scarce. The first came from Dallas and the second one from a warehouse in St.Louis. From talking to him, they seemed to be specific to the year of the truck, but I don't know for sure.

 

are they ground switched?

Travis

 

I hooked one wire up to the orange and blue wire and another to the brown and white wire under the hood of the relay box closest to the front. Then ran it into a 3-way switch in cab one down is 4HI 2down is 4low and one up is 2wd. if ya want ill get a picture of it up for yall.

 

I hooked one wire up to the orange and blue wire and another to the brown and white wire under the hood of the relay box closest to the front. Then ran it into a 3-way switch in cab one down is 4HI 2down is 4low and one up is 2wd. if ya want ill get a picture of it up in a hour or so for yall.

that would be nice, I don't have to think when mechanics are involved cus they usually will only fit one way but electrical makes my head hurt cus then I have to think:doh:

 

The first picture is the relay box that you will need to use, with the cover removed. The second picture is with the loom removed from the wires andthe blue and orange wire that you will need to tap into I cut open this wire and wraped a wire around it, then sodered it up and put the heat shrink on it and then taped it up to ensure no shorts the brown wire is on the bottom of all of those wires. the third picture is of the 3way switch its the chrome switch. If you want any other pictures tell me waht you want them of.

 

Hi, I have a 02 excursion 7.3 and just replaced a bad transfer case motor. I don't get any power down to the transfer case motor. Fuses good. Possibly bad gem. I am unclear how to wire to the switch. Where did you get the switch. I can make my motor engage into 4 wd and back to 2 wd by a hot to orange and ground to yellow and then reversing polarity. My cell is 314-409-5732. I am south of St louis approximate 30 mi.. Thanks

 

That would be sweat... if it was my own truck!!

Travis

 

I love having this more than the factory switch for some reason it just looks cleaner and to get rid of the old switch I cut out the old switch hole and mounted an XM reciever in their so it looks ike it never can with the switch.

 

Do you manually lock your hubs? If you wire the switch as you did, it bypasses the GEM which has all the safety controls for 4-low (i.e. brake pressed and neutral). To me it doesn't sound safe, it looks like you can accidentally force a 4-low shift even though you haven't met the protocol of being at a standstill. There are 20 or so wires in the GEM harness that control the ESOF system alone.

I have MSOF so I don't need the switch at all, but I also have to get out and lock the hubs.

 

This mod does require you to be smarter than your truck. How did we ever get by without all of there safety things back in the old days. It's a wonder all of us old farts ain't dead from unsafe vehicles.

 

I have Warn maunual locking hubs I have always hated vaccum auto locks. I use the switch the same way I would if it were still hooked to the other switch as long as you think of it like its the old switch its still its just as safe. Also the only reason to use such a switch was that the old system failed.

 

got her figured out it was none of the above, turns out the fuse was loose in the fuse panel!

travis

 

:doh: Don't ya love it when they are easy fixes.

 

doubt your problem is that difficult as well..

try replacing the high-to-low and low-to-high relays in the relay center next to the PDC under the hood..

my bet is it works.

 

Hi I am trying to bypass my gem on my 02'excursion 7.3 and im unclear how to wire a switch like you. My email is fredm651@yahoo.com. Or call my cell at 314-409-5732. Thanks Fred

 

I know this is an old thread, but i too have a 4x4 problems and want to do this switch method. Can better describe how u hooked up to the switch, and type of 3 position switch u used. Is is the common on-off-on etc. Thanks!

Bryan

 

Hey guys sorry havent been on here much ill have to go take a look this weekend the trucks at my other farm and im busy working 12 hours days rest of the week i may get a chance on friday to take a look at it and to try and remember it all dont want to give anybody bad info on how to hook this up but the switch itself was just a simple 3 way switch i picked up at oreillys.

 

Update? Is your 3 way switch hot? Or is the wires hot and your grounding them?

 

Don't mean to bring this thread back from the dead, but im having 4wd issues also and i've narrowed it down to the GEM. I'm gonna take it to the dealership so it can be checked, and if it's bad this seems like a easy and much cheaper solution. How the switch is wired up would be very helpful info.

 

Well I would like to know the diagnosis on the GEM, I posted the other day but not much has replied to. And it's giving me fits. I have power to everything except the the transfer case motor, no lights, relays are not switching, they are good and there is power there, just not power from dash to switch it..

 

Hey all on this old thread. Did anyone try to do the GEM bypass like JuststokeIT did? Just wondering if it worked. I'm trying to decide between converting my NV273 from electric shift to manual or try this bypass.

 

If anyone was thinking of doing this, I think the wires need grounded in order for it to work. If you jumper from the orange/blue wire to a ground, it causes the transfer case shift motor to go to 4x4. Not sure if thats any help or not.

 

I know this is a way old thread. But seems to be a continuous problem. I am wanting to wire up the switch. But I see we are grounding the relays but what puts it back to 2 H??

 

Are you still online? I have a question about your 4wd bypass that you did. Thank you in advance

 

Why don't you just change it from auto switch to manual you can do this and keep your v same transfer case.....just a thought