Hi,
I have a 1999 F-350 V-10 Automatic.

Question: If the vacuum Hub Lock Solenoid fails can you still get the transfer case to engage if choosing LOCK on the hubs

My ESOF does not work and I can't figure it out. The dash switch when turned to 4HI or Lo does not turn on the 4x4 mode light and the transfer case does not engage. I figure there is something wrong with the vacuum.

Is there a way to jump the wires on the ESOF switch to engage the transfercase motor??????????????????????

I examined all vacuum lines going to each hub and found no problems.
All fuses and relays are good.
The 4hi & lo lights work on the cluster gage.
I was told that if any of the vent positions fail that I have a vacuum problem since the Hub solenoid and vents share the same vacuum. Mine work good.

I was confused on a certain relay:
My owners manual shows the under the HOOD #40 fuse/relay to be ESOF
relay #1 & #2. That fuse box only goes up Fuse #37. Therefore I assume that Ford is talking about the #1 relay under the dash since that is the only #1 relay. My space for the #2 relay Reads "Not Used".

My owners manual for the under the DASH fuse box, shows the #1 relay as Interior Lamp Relay.

Whats is the right train of thought???????????????????

How can I fake the transfercase motor to work w/o vacuum.

Thanks, John
Harrison, Arkansas

 

Answer: YES lock your hubs and the tx case will still work independently.

The switch on the dash controls sends a signal to the ECM which controls two TOTALY seperate 4x4 systems.
One is the tx case motor, the other is the vacumn system.
If one or the other is not reponding, so what? It is to dumb to know and it will try to active both anyway.
The only feedback is the light on the dash, it is an indication of the tx case position. The vacumn pump, hubs and the whole front axle could have fallen of the truck 3 winters ago and your ECM would not know it.
It the dash light does not light when you turn the switch then the problem is definately with your tx case motor, not the vacumn.

Follow this thread for info on exactly your problem
https://www.ford-trucks.com/forums/5...with-esof.html

 

MUSICMAN, That was great information, plain and simple. Everyone else I talk to are so hung up on how the ESOF vacuum works and explain when the vacuum comes on and how many pounds it will hold ete, etc......... I've put you on my important person list!

Let me ask you this, If the tx motor is still good and there is no light activation when switching the dash switch, could it be a bad GEM. Or, no dash lights means directly bad TX motor.

Thanks so much for the help, John
Harrison, Arkansas
1999 F-350 V10 Auto Crewcab LWB Dually

 

Johnny, I tried to reply to you email , but you have blocked out revieving personal emails on your FTE settings.

Anyway, sorry I haven't had experience with any of the fuses or relays to the 4x4 circuits.
I know that if you remove the tx motor and crack the transfer case by hand (with a socket wrench) the light on the dash will light.
Here is a copy of the post I wrote from the thread listed above incase you didn't see it.
Check voltages at the connector of the trannsfer case motor.

If you remove the motor you can also apply 12v to it to the pins to check the movement of the motor.

With the motor off truck, you can crank the transfer case with a socket wrench (3/8 square drive I think) to selection of the 4x4 (2wd-4HI-4LO) and this should light the dash light (with ignition key turned part on).

Be sure to mark the position of the crank nub and the motor spindle BEFORE you play with it so you can put the motor back on afterwards!

On my 2000 F250 I found the motor was powered and turning but the plastic worm gear inside had stripped, so it was making the noise of moving but not actually turning tha transfer case nub.

 

Thanks for the reply. I replaced all of my relays and checked all fuses related to the ESOF. With a test light I tested the wire coming off the TX motor, NO Power. So, if I manually move the position on the TX, and it goes in any 4x4 mode, how is this getting a signal to the ESOF dash switch if the wire is disconnected. If I'm not getting power to the TX motor then it's either a bad GEM or switch. You can, If you like personally email me at prayers1@peoplepc.com
Thanks, John

 

The power and switch for the dash light is somewhere inside the transfer case gear housing, the tx motor simply shifts the gear, the same way that a manual 4x4 shift lever would.

 

Thanks for the quick reply,
I guess you have a lot of time on your hands with that snow that never seems to stop falling. I just got off the Weather Channel. I can't believe the snow amounts your getting. Hope you have chains.

OK, I understand your answer. So If I turn the shaft within the transfere case, it will send a signal to the ESOF switch. Then what is the wire going to the transfercase motor, where is it coming from? I tested that wire with a test light and it had no power. Is it coming from the GEM. Does that mean the GEM is shot. I don't know much about the GEM's but shouldn't other things be effected and shouldn't there be a code.
Keep Warm!
John

 

A lot of time on my hands eh!
What with chasing beavers out of the maple syrup mines and skinning moose to make furry hats and gloves, there's barely time to play 8 hours of hockey before sunset.

OH Canada, our home and native land...........

 

I'm having a similar problem

My 01 V10 Wouldn't go into 4x4 last saturday so I just left the switch on 4x4 and after about 20 miles, it started working but the light on the dash didn't come on. It came on yesterday while I was plowing, twice for a few minutes each time, but today the light's off and the darn thing won't shift back to 2wd.

If I take the tx motor off, it sounds like I can turn the shaft with a wrench. Does the shaft just turn a 1/4 turn or so in either direction to lock/unlock?

Any ideas?

Thanks,
Steve

 

Yes about 1/4 turn from 2wd to 4low with 4hi somewhere in the middle.

 

What the Heck!!


I started reading about the Shift on the fly switch not working thinking how lucky I was not having any problems with my F-350 when this morning I switched into 4 high and low and behold nothing happened. No lights, no noises, just a dead switch. I guess I will have to spend this fine Sunday trying to fix it.

I removed the Ford hubs and replaced them with Warn manual hubs a couple of years ago with no problems till now?

Where do I start?