I Have done this and works great. One thing I RECOMMEND Is to get a switch that is Spring loaded back to center to keep from burning up transfer motor if left un up or down mod. Our if someone else drives vech forgets to switch back to center.
You would be surprised how easy it is to access the GEM. However I dont think it would have solved your problem. I think you did this the best way. Good Vid.
You actually did a fantastic job of writing out a wiring plan. I have a Ford Ranger with the same type of transfer case. And I will use your method as a way to get it to work if all else fails. Thank you for posting your video!
Great video! I finally did this and it works well. It Takes some practice to get a feel for it since no light indicators work. I put my fuse where I could reach it easily and then pull the fuse until snow is coming to kill the circuit until needed. Thanks again I would have probably not tried this without your vid.
Good information here. The video was on point. And the comments were helpful as well. I’m not doing this. I’ll just order the switch and keep looking for the actual problem. Foot note here someone come up with a manual shift linkage that does away with the electronic BS. Vacuum on vacuum off on the front hubs is no big deal but I don’t like that crape ether. Thanks that is all
He uses a double pole double throw switch. on the switch, the middle two connections are for 12V + and 12V-. The drawing he did shows he connects short jumper wires from each connection on one end of the switch to the opposite side connections of the switch to change the polarity (direction motor will travel)(like drawing an X from the corner connectors of the switch). This changes motor direction when he moves switch from up position to down position (or vice-versa). Old 4x4's had a lever that you pulled down about 2 inches to go from 2xH to 4xH, then you moved it down another 2 inches to go into Neutral then another two inches to go into 4xL. This electric motor is just moving that lever into each one of the positions (hear the clunk in the video). If you move the switch one direction it will go in the above order, when you move it the other direction it shifts the transfer case back from 4xL (clunk) to N... then shifts to 4xH (clunk) then shifts to 2xH (last clunk). You must return the switch to the center position (see other comment about buying a switch that is Momentary (returns to off position by itself like your window switches) for safety... best application for this if you are absent minded. pg 112 of the 1998 Ford Expedition owner's manual shows Ford uses a 30Amp for the shift on the fly Expeditions... If you intend to do this use absolutely no higher amperage fuse than that. Keep in mind that this thing could actually get stuck between gear positions and leave your machine in Neutral... as mine did the second time I used it. Better make sure you know what you are doing if you want to attempt this. If you are parked on a hill and accidentally stick it in between gears, you will roll (obviously you have brakes!), I do not recommend doing this, but it did work for me to trouble shoot my 4X4 problems until I replaced the motor (which now only cost about $50-60USD.
I've never removed the GEM module so don't know how much trouble it is. But before going to all the trouble of installing a whole new switch that may or may not work properly, the transfer case relay/module is right up behind the tach, under the dash. There is also a switch/relay to the right under the snap-in oval piece on top of the passenger side dash. If you turn on your 4WD switch and you hear that switch going on and off but you don't hear the relay clicking or it only clicks intermittently, you probably have a bad relay. If the switch under the oval piece isn't clicking it's more than likely that part. Both are easy to get to. For the switch just pop the oval piece and there it is. For the relay it's a bit tougher but even on your first try it shouldn't take more than a half hour in and out. You pop the stereo surround and duct piece out. Then you pop the yoke over the steering column out. Remove the light switch assembly [look up how to do it] and remove about six screws and pop the headlight/instrument cluster surround out. Remove six more screws and pop the dash top off. Voila, there's the module sitting right on top. $30-40 bucks for one on ebay. Probably much less in a junkyard. Only having 4Lo if you're going any distance or you're on the highway in the snow is a real pain. Whether the switch in the video will harm the motor I don't know. I do know the factory switch is only hot for a moment to shift the transfer case and then turns off. When the switch in this video is on it stays hot even after the transfer case is shifted.
I have a 07 f 150. we had to replace a wiring harness. it operates the 4x4. it went to the iwe solenoid. we could only find a 2 wheel drive wiring harness. would this video work on my truck to? How would I get the iwe solenoid to work?
The front solenoid vacc valves can stay on the engaged position all the time, it won't hurt anything but fuel economy just little. It would be really easy to just put a switch to the ground side of them to have them engage and disengage front differential. Can ask how if want to that.
Is the switch set up for in the up position it's in 4WD Hi and the middle position is Neutral witch puts it in 2WD and the bottom position is 4WD Lo????
I may have to do this. I have tried replacing the twin relay under the dash with a new one due to no clicking and 4x4 doing nothing when switch is switched checked and solenoids both good. I dont think its the gem because everything else works. The relay was only 13 on amazon and took about 30 min to get off the truck and 5 to desolder and desolder. The next thing I think it may be is the sensor unit beside the actuator motor any comment would be greatly appreciated
so i just bought this truck. literally this truck. and i cant get it over 35mph. the switch isnt making the 4x4 engage. idk what the deal is. what do i do?
Normally the transfer case is considered in neutral or 2hi and when the switch you made goes into neutral then it makes the case turn to 2H so is there an up for 4H and down for 4L? Is that what you mean but up and down, one being 4h and the other 4L and middle is 2H or neutral?
how do you test the transfer case motor to see if its working and as to the diagram for the switch its not showing what to do with the center contacts on the switch
I think just leave the hot 12v connected but disconnect the ground side and put individual switches on to ground one solenoid or the other for 4wd (solenoid closest to side of truck) or 2wd, then this also bypasses the GEM
After you direct the 12 volts to turn the motor all the way what disconnect the constant voltage to the motor or else will it blow the motor or wiring as the motor will keep trying to engage unless you have some feedback to stop the current or is this done inside the motor terminals at the case?
Thor Thunder the power won't stop on its own, once the transfer case is on 4wd or back to 2wd you switch the switch back to the neutral position to cut the power
That is what i thought so you have to flip it back quickly to stop the flow of current which will not stop on its own. Thanks, otherwise i might have left it in that position. So, up is locked in and middle is neutral and down will lock it the other way and then you got to go back to neutral again. I think i can remember this and not burn it thus the fuse will let me know for sure. Now, is there a way to install a control simply to leave it in either up or down that will disengage it? I know the regular circuit does it somehow but how?
How you put it back in 2wd if up is 4L and down is 4H do you have to click the switch up again to make the motor turn back on 2wd then set it the middle position ?
The 4x4 lights should still work, but i see they do not. The shift motor on the transfer case has position switches that tell the gem module what 4x4 mode the transfer case is in, so it can send signals to the appropriate selonoids that operate the front axles acumulator. Those switches rotate with transfer case motors position. All the switches do is open and close circuits for the gem module, as the motor roates, the switches rotate with it. You sure you just don't have a bad transfer case motor?... and are you really gettin it in 4x4 mode? I'm not sayin your switch won't work, I'm just sayin it appears you may have other issues the switch you put in isn't resolving.
Thanks for inspiring me to do this. I'm planning to add 4wd to my 2wd Jeep Liberty. I bought the transfer case and made a custom electronic shifter, like you did, since my computer doesn't have any 4wd functionality. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MjTQ-H4XXqI.html
Ryle Smartlowit the tranfercase motor turns one way to the other, all the way on one side is 2hi, middle 4hi and 4lo all the way in the other end. I guess if you really must have 4hi you can just time the flip of the switch (I'd say 1.5 secs would have you in 4hi)
Actually takes 5 min to pull the fuse box/gem assembly. Remove the 2 10mm bolt on block connectors on bottom of fuse box, then unbolt the two bolts (8mm) at top and two nuts at bottom to (10mm) that holds the fuse box in. There’s a small locking tab that holds the fuse block in as well near the bottom and latches to the dash support frame and you just push to release the fuse box. Then carefully push fuse box away from dash toward firewall and lower 1/2 way down. There’s 3 gray plugs on the side. Use a flat head,or similar, to carefully remove the connectors or get your hand in there to push the lock tabs in and pull out. Once all three are removed, wiggle fuse box out. No need to tear apart dash. Once it’s out, try cleaning all the connector ports with Crc electrical cleaner or mass air flow sensor cleaner. Also remove the 3 screws holding the gem to back of fuse block. Clean that shit too. I always open them up to inspect the circuit board. Typical for the 97-98 f150 expy to loose 4low while no other problems exist. The condensation builds up around the fuse box (not so much a leaky windshield causing water to ride down the harness)but definitely leaky windshield does contribute to more condensation and moisture around that are. Which in turns builds corrosion on bottom of circuit board for gem. You can not close off the vent holes all around the gem because it needs to stay cool. Anyways, try giving it and those two big block connectors a good hose down and use a nylon wire brush. It’s a 50/50 chance of it being gem vs the bad fuse block. Both from corrosion. When you reassemble, use the hell out of dielectric grease, but not so much on the terminals of the connectors. Then throw it back in half way and test everything. If it’s still not working. Get a on-off-on 3 wire switch and momentary push button. Or just a 3 way momentary rocker switch. And some wire connectors for whatever switch you go with plus the round terminals. And some 14-16 ga wire. Connector your 14ga wire to a terminal and bolt it to the body inside the cab. A good place is by the e-brake or the metal support in front of the fuse block nuts. Then run the wire to one side of your push button momentary switch. Next run a wire to middle of on-off-on switch. Now run one wire from top of switch and use a bit splice connector to connect that wire to the brown wire with white stripe on the bottom of the three gray connectors. It should be 5th pin from the left on the bottom row of terminals. Next run the last wire from bottom of on-off-on switch to the wire next to the brown one that’s color is orange with light blue stripe. Now connect all the connectors up and don’t forget about the big block ones for fuse box and put it in 4hi like you normally would with factory switch. Then go to neutral with foot on the brake and push your 3 way switch up (which you can leave there) and push the button switch until transfer case motor switches and lights on dash come on. To come out or back to 4hi, put toggle switch down and push button until light goes out and you hear motor shift. To get back to 2wd, you’ll use your normal switch. The 4wd solenoid don’t need to be worried about because they engage with the normal working system when you put it in 4hi. Nothing else happens other than motor shifting when going from 4hi to 4lo or vise versa. Also to add the gem switches most of everything it controls with a ground and not positive polarity. So it’s easier than most think to bypass the gem with different things
