why wont my four wheel drive engage, worked great last year and now nothing

check the 4x4 fuse,switch to 4x4 could be bad,it also has a small motor on back of transfer case it could have come unpluged or gone bad.

if the 4x4 light comes on do you think it may still be as simple as a fuse?

yes it could be,the 4x4 fuse is usualy in fuse box under dash,some are under the hood fuse box it will say 4x4 on fuse pannell,also you may want to have the hub assem on front to be checked to see if splines are striped,if just not enguadeing,fuse or the motor mentioned in other post.ford is bad for this motor going bad.

Thanks a lot, I really appreciate your prompt and knowledgable answers. You are a blessing!

No problem,hope I was of some help,let me know how it turns out.

mine was maddening, and was a corroded conductor under the hood. Pull the codes and see if you have a shift relay code. But check your fuses and the shift relays under the hood. Its a pair that fwd/rev the polarity to the shift motor to engage/disengage the 4x4......IF your fuses are good and IF youve replaced both relays under the hood (you can temp swap w any other of the relays under the hood they are the same) then look at the drain hole under the relay housing and look for any whitish green powder around the drain hole. Its a clear indication of copper corroding.....dissassemble the housing and repair.....

where are the fuses located dont have any lables on fuse panel

good question mine either but i do numer 17 is one of them, it is a large fuse under the hood'

30 amp inch wide

my f-250 will not come out of 4x4 and it wont start

i have replaced the shift motor the dash switch and the relays. the truck is stuck in four low. HELP!!!!!

look under the two shift relays under the hood, likey you will find white/greenish powder around the drain hole under the assembly. here a conductor has corroded through and wont allow you to shift out. additionaly, truck must be in neutral to shift out of low4x4. you can remove the shift motor and shift it out with a cresent wrench on the shift shaft. make sure its in neutral, parking brake on.

i give that a shot. the thing i do not get is the dash light is saying its not even in four wheel

ralays are clean and greased and still nothing

the issue is in the position switch then, near the shift motor, it gives the feedback loop back. the factory sm gives a full step by step pin point test for all those conductors. I dont have my 99 f250 anymore, dont need the manuals, its a stack of books about 10" high that cover everything on that truck, yours for 120$ plus shipping if you want them.

OR, it may still be the dash switch, pry the cover off one shift relay, ensure both are in their sockets, and push on the tab of the relay....it should shift the 4x4, If not, switch the relays from one socket to the other and try again. you will have top swap them to get it to go to the opposite direction or just pry the covers off both and see if it will switch back and forth with your thumb on the contactor of the relay...if it does your issue is in the dash switch.......mj

Thanks for the help

I just ran into the same problem I looked it up and clicked my way to this thread and I already did everything that was said so have you figured out the problem

To eliminate a control issue. Pull the cover off two shift relays and push the contactor with your finger alternating from one to the other. That bypasses all controls and control power. ....do that and let me know what you find.

Jackmanmachine...I'm having the same problem with my 2010 F150 where dash control knob seems to do nothing. Also, no indicator lights come on in the info screen saying 4x4 hi or Lo. I've been wondering if it's the switch itself or something else. Trying to narrow down what's causing the issue and will need 4WD soon. Where are the shift relays? Any other suggestions on what to check?

dont know on the 2010, google the location, but you get no feedback untill the shift motor makes, IF its the relays, thats simp[le to check the same relays are used all over the ford, just swap with another and see if you get control. IF nothing changes and IF the relay fuse isnt blown then I would gently pry the cover off two relays , place them in the shift sockets and with my finger push the contactor in till it makes. if its in your wiring then the trans will shift..

Great. Thx. I will try this first and post what happens.

Okay I have. F250 4x4 was working great turned it off now no 4x4 light will light up ant ideals ?

jackman, we can manually shift with the covers off the relays. but no power to switch on the dash. what to ck next?

Lift the block the relays are plugged into, look for greenish white powder around the drain hole. If none then open and inspect the inside, beneath the relays. Look for any signs of corrosion. Your problem is prob there. The step after that is to open the harness at the shift motor and with a multi meter do a point to point continuity check on the conductors from the shift motor to the switch and relay sockets. I'm betting corroded wire under relay

The wiring from the relay to shift motor is good. Fuse and wiring to relay is good. No current to switch and dash light indicator is not on. Control module has been replaced. (used unit)

If you've done the continuity test but not looked under the relays to verify you not done. On my it PASSED the continuity test. When the probe was pushed into the relay socket the downward pressure was enough to close the open circuit. .. you have to look under here.

we took the the bottom off the the relay box under the hood, by the fuse panel. Its clean no corosion.

then if im understanding this? youve validated all the wiring with a point to point test? (this takes two people with long test leads on the meter to do) AND youve replaced the position indicator under the truck AND all the relays are good, all the fuses are good and you still dont have voltage at the switch in the truck....? as unlikely as it can be the only thing left is the GEM module.....about 230$ IF you go this route my recommendation, have the dealer instal it, if it doesnt correct the problem then make them take it back, they will bitch but since they put it in and the problem wasnt solved then they have to take it back. or find one on ebay. there may also be a battery saver relay and another relay involved, I have to wait and when I get home look at my service manual to be certain. what year is yours??

We did not do a point to point test, we didnt have a diagram. When looking for an online wiring diagram I ran across this site. Some the posts seemed close to my problem. Cant blame a guy for looking for a quick fix. I do have access to alldata and plan a more educated search tomoro. Thanks Johnny

I have a 2010 Ford F 150 and sometimes it shifts to 4X4 and sometimes it doesnt. When it doesnt engage it says to check 4X4. any thoughts

I would look under the relay block.....you prob will find a corroded conductor...directly under the relay socket.....

and also check back on the strings and read them all leading upto now....

I have an issue with transfer case moter tring to engage after turnning engine off any ideas?

Stuck or fused shift relay.....pretty the cover off both shift relays and inspect. Cheap to replace, standard cube relay...

Pry not pretty

Replaced relays srill does it

Can anyone help!!! I have a 2002 F250 XL with the 4.2l and in 4x4 i dont have a light come up on my dash. I cant even see if i have a dash light in 4x4. Should i have one?? everything with the hubs locking in is fine and the ESOF works fine but no light on the dash???

how long is it going how much is it going to cost for me to talk to this man because I can go to the Ford place here in town in the morning and get the information for free was just aggravated when it to knowwanted to know

We have a 2011 F250 with electronic 4x4 switch on dash. Our 4X4 quit working and after exhaustive searching we were nearly ready to sell the truck. Finally found the problem. Where the wires come off of the transfer case, they are near the front driveline about 6 to 8 inches up from transfer case plug. They apparently got rubbed at some time by the driveline and a couple became frayed. Very hard to see and not very easy to patch. Actually felt it when I was running fingers over the line. We were at wits end and it is crazy to have wires that close to moving parts. Hope this helps someone.

I have a 2003 and when I switch the switch on the dash I can feel the transfer case change but the front wheels won't pull, what do you suggest looking for? Thanks

I own two Fords and I have found that you really need to exercise the transfer case regularly. If you do then they will work smoothly when you need them. Just engage them at least once a month, in and out a couple of times and go into low range too. You can do this on a a straight section of paved road but drive straight so that you don't bind up the 4wd system.

Driving your Ford in 4wd on dry pavement will mess up your transfer case and make it really hard to get out of 4wd. Reserve 4wd for slick roads and dirt.

So on my 2001, im having the same issue. Relays are good, fuses are good, no corrosion in the relay box. good transfer case motor, but 4wd will not work. used to work perfect. no light on the dash absolutely nothing when I flip the switch. One time when I was underneath I was tugging on wires and my dad was in it turning the knob, I got it to go into 4wd. then right back out. Coincidence? or is there a bad wire you think? however I've looked through all the wiring over and over between the relays and the t case, looks fine, is there anywhere rubbing or something is common, some where hidden? any help is much appreciated, thank you.

Mine won't engage and makes a roaring noise

Have a 2011 F250 w/ the auto-manual hubs. When I tried to engage auto 4x4 it would scroll '4x4 shift in progress' on display then 'check 4x4' w/ a wrench, but not engage. Checked vacation lines & fuses all seemed good so I took it in and all it was somehow the solenoid got unplugged.

I have a 2007 manual shift transfer case , while driving in 2wd my 4 hi light will flash and hubs will try to engage , stop and check wires at pcm and upon moving them will hear actuator clicking on and off and 4hi light will come on and off , so must be a bad wire as to new transfer case , New hub assemblies new actuator new 4x4 shift indicator switch , does wires from-shift indicator switch go straight to pcm , trying to locate a possibly bad wire

And from what I’ve read is the switch received a ground which indicates it’s in 4wd ,so both the wires are hot ?so guessing I got a bad spot and wires grounding out , trying to find it before all the new stuff gets destroyed again

1999---2003 F-250 ,1st check the fuse num 17 and 18 underhood (engine compartment) 2nd vehicle runs in Park position have some one switch to 4x4 and back to 2WD feel the click on the Transfer case connector ,most popular connector corrosion, unplugged ,full of mud dirty , broken locking latch ,wire rubbing against the chasie ......etc

I have a 2000 f250 super duty and 4wd switch doesn't nothing

Have a 2010 F250 4x4 and the it will go in High but it want go in low any suggestions

I HAVE AN 03 F-250 7.3 I HAVE NO POWER TO THE SELECTOR SWITCH ON DASH I HAVE CHECKED FOR COROSION ISSUES AND I HAVE CHANGED RELAYS AROUND I HAVE HOCKED JUMPER WIRES TO TRANSFER CASE MOTOR AND IT SHIFTES LIKE IT SHOULD BUT WILL NOT SHIFT OFF THE SWITCH JUST LOOKING FOR MORE IDEAS ON WHAT TO LOOK AT I WAS TOLD IT COULD BE THE BODY CONTROL MODULE CAUSE IT IS BEHIND THE INNER FENDER ON DR SIDE