'O5 4x4 stopped working checked all fuses all ok. I can't find anything in the Manuel on what relays are under the hood are for the esof. If anyOne knows which relays they are or to check it would be greatly appreciated.

Thanks in advance.

 

What part of it isn't working? Do the 4x4 lights come on? Have you tried locking the hubs?

 

The fuses and relays will be in this PDF.

When I have some time to get to my computer I can post the
ESOF diagnostics and pin point testing for your year.

 

Looks like it’s in Aux box 3 I read on one thread that you should be able to switch the relays. One controls the on and the other the off to see if that’s the source of the issue. The 4x4 light works on the dash when the keys first turned and it doesn’t appear to be hub related tried both locked and unlocked. Haven’t crawled under to check for power at the connector hoping to try this first. From what I’ve read this is the most common problem - relay.

Any idea where aux 3 is located thinking it’s under the fuse box under the hood.

really appreciate the help fellas.

 

Look in the PDF I just posted and you will find that box up by the driver side battery.

 

f

 

Here is that other PDF.

 

Just had this happen. My fix was to replace the two under the hood relays. Here are some suggestions.

Pull the two ESOF relays. Go into the power panel under the steering column and find a relay that you know works. Substitute each of the ESOF relays for the known good relay, to see which one is bad.

If that does not work, remove the dash switch. It is the next weak link. Take it apart. Be careful not to loose the spring and ball bearing. Clean the three rotating contacts and the circuit board ribbons. Put some dielectric grease on the contacts and reassemble.

Next, check the ESOF select valve. This applies vacuum to the hubs. It is above the vacuum pump. OBTW check that the vacuum pump is operating.

Again, relay contacts pit and burn over time, depending on frequency of use and current being carried. They use to be repairable, but the new design does not allow that for obvious reasons. The only option is to take it apart and spray some contact cleaner on the contacts. This may remove some of the burnt contact residue but will not remove the putting.

Ed

 

I have the same problem right now. 4wd was working a couple days ago now just doesnt do anything. Im suspecting falty motor as i have swapped the two relays and still nothing, (unless both those relays are bad i have not checked them with a multimeter yet) and the 4x4 lights come on when i start the truck.

 

It’s been -20c here last couple days so I haven’t been a able to work on it. Little frustrating 4wd was working fine couple weeks ago and now nothing - same symptoms.

curious if the forscan would pick up any codes ?

please post what you find. Thank you

 

ForScan will read the codes.

 

So just to clarify...the 4x4 light comes on when you turn the key on, but does not come on when you flip ESOF switch?

 

Did you read the pinpoint testing PDF I posted?

 

The pdfs that Yahiko posted will tell you how to troubleshoot but if you dont understand them I did it step by step with photos when mine **** the bed. If you follow my thread you should be able to see if the electrical side is good.
https://www.ford-trucks.com/forums/1516220-conclusion-to-wont-come-out-of-4x4.html

 

Really appreciate the help. Finally got warm enough to look at the truck again, I ran the Forscan and got P1812 and P1876. The trouble shoot guide has me starting with the solenoid on the passenger side. I'm trying to get ohm readings either my voltage meter sucks or I'm doing something wrong. Anyway hoping some of these DTCs could short cut what might be the issue. Just to clarify, the lights come up on KO, 4 wheel drive won't engage can't hear anything happening under the hood. I have the manual hubs there locked, tried rolling both 4H and 4L and nothing. I use 4WD all the time just stopped working out of the blue.











Great info on that previous thread I'm going to work my way through it and see if it will tell me anything. Cheers.