Ok I've done some searching and reading and really haven't found a answer. My 99 f250 sd 4x4 v10 with a automatic transmission stock hubs with ESOF. I checked the fuses under steering wheel. All good. Showing no error codes. Replaced vacuum lines. I've been driving it for some time only using the lock outs on the hub. Whats different is there is no light on dash stating 2wd, 4wd or low. And when manually locked they don't move in snow. new hubs? I don't really care about switching with ESOF I just need 4WD for plowing!
ANY tips will be well appreciated. Thanks

 

Does it go into low range?

If it's not spinning with the hubs in manual lock, it could be the transfer case solenoid is not pulling in.

 

well installed the transfer case solenoid and it didnt change anything. Nice thing is it took me five minutes to test, remove then put back in box. It took me 12 days to find time to do the work. I thought it was going to take alot longer. well any more tips? the motor now?

 

So you're saying it's not actually engaging the transfer case? Have you tried the relays under the hood? I believe there's 2 of them, one controls shifts from 2hi - 4hi - 4low, and the other does the reverse - you might swap them and see if you're then stuck in 4wd.

 

Ya no lights on dash, no sound of it engaging. Why don't my manual locks work? I thought that they override dash switch? where are these relays under hood?

 

Whenever you check fuses, it is important to ohm them out. There may be a break in the fuse that you cannot see. Pull any applicable relays, clean the blades and you could swap them out too. Easy stuff first....

 

Sorry, I was gone for a couple days. Did you ever get this resolved? If the transfer case isn't engaging and transferring power to the front axle, it won't matter what position the hubs are in. The manual lock over-ride is only for when the vacuum assist won't automatically lock the hubs to the axle, nothing to do w/ providing power to the front axle, just being able to use that power.

Somewhere on here there's a sort of troubleshooting manual for the ESOF system, for the life of me I can't find it though. Do a search though and maybe you'll run across it or piece enought together to figure it out. I've got the old simple manual system so I don't know a whole lot about the ESOF, but I'm thinking if your dash lights aren't working, then the shift motor on the transfer case isn't sending the signal to the light, which could mean it's bad or it's a problem further up the line. I think your truck has a GEM module which controls that, could also be your dash switch.

In answer to your question though, those relays are under the hood, they've changed locations around between they years but look for a covered box under the hood. Your owners manual will tell you what to look for.

 

Here is a link to my transfer case shift diagnostic. Since you have a 99 and I have an 04, none of the fuse numbers will match, and I will refer to a 4WD control module where you will have a GEM module. Otherwise it is the same.

When checking fuses, check anything in your Owner's Manual that refers to the GEM module or any "feed" (Run/Start feed, etc.) Check them with a test light. Never rely on a visual check. I believe in a '99 the shift motor relays are in a box next to the Power Distribution Box under the hood.

https://www.ford-trucks.com/forums/1...l#post10605244

 

Pulled motor apart. Had to cut due to seized torks screws. I knew it was shot so saved time and used a sawsall.


Little gears shattered during removal.

Far right is the plastic part of motor I think this part tells GEM that its in 4w 2w or low. Also must run light on dash as well.

The culprit. Looks like this is where it was broken.

(Top finger) shaft spins free when (bottom finger) motor isn't moving.

How I tested it while mounted on truck then after I removed it.


When I was running through diagnosing things the motor would run. Which fooled me for a bit........

HOPE THIS HELPS. Glad I didn't go throwing parts at it.

 

Now of to Advanced auto to pick up a new motor. carmon for $125.
so I replace some relays for $13 each and hopefully this $125 will do the trick.

Thanks peoples for posting your issues and repairs. That helped me find mine.

 

Update. This solved my problem. Never had a issue since.

 

Thanks for the update, its always nice to read that the fix held...