I was up in the mountains last weekend with my brother, me in the 02 F350, he in his 86 Dodge. We were playing around in a creek bed, when I turned to climb out, I noticed that my rear wheels were spinning, but my fronts weren't. I tried turning the selector switch for the T-case again. Nothing. I got out and put my hubs from "Auto" to "Locked", then tried again. Nothing. I ended up having to back up across the stream, and get a run at it and just blast up the bank as fast as I could go! We got back up on the trail, eventually, but as we had a 120 mile drive home and it was getting dark, I didn't feel like doing any troubleshooting right then.

I'm just looking for a little education on how the auto T-case system works. I imagine that the switch runs a solenoid or a motor on the back of the tranfer case to enact the shifting. I would also imagine that there is a fuse in the system too. I thought I would look for a blown fuse first, then check for power at the switch. Then move on to the solenoid/motor thinger on the T-case itself.

What do you guys/gals who are more familiar with this system think? Am I heading in the right direction?

 

I have an 02 F250 and the Switch went out on me about 4 months ago. I just took the switch apart and had to clean up the connections and add a little electronic grease. Good as new. If that doesnt work then you may have an isue with the solenoid on the t-case.

 

I like solutions that dont require any cash expendetures! Here's to hoping it's just the switch!

 

Ahhh the good Ole Electric 4x4 switch,,,, "LET DOWN",,,,Will it work today,,,or not ???
Not wishing those problems on anyone,,,But,,,,,That's exactly why I only will buy a 4x4 truck with the manual hubs and transfere case,,lock the hubs,,pull the lever,,,,and 99.9% of the time you have 4x4,,,not hoping some electrical switch or wire did'nt get a bug up it's butt and decide not to work for you,,in your moment of need.

Does'nt matter if it dont work when you on a paved road,,,get snow,,or mud,,when you relly need it,,and it not there for you,,,,

 

Put your key in the the ignition and turn it on, but dont start the truck. Leave the door open and turn the ESOF switch to 4x4 High and you should be able to hear the motor clicking on the t-case. If not, check the connection to the motor as it could have a bad connection there. Also if you have a DMM you can see if you are getting any voltage there as well.

 

I used to think that way too, but then when looking for a used truck and not being able to find one with a manual xfer case, I came to realize that these trucks won't run at all without depending on electrical components, from the accelerator pedal to the fuel injectors. If you really are concerned about depending on electronics, you should never fly.

I'm not picking on anyone, just voicing my own thoughts that led me to not worry about that stuff and enjoy the convienience of not having to get out of my truck to lock the hubs each time I need four wheel drive (which is often).

I actually think the best option would be the auto hubs (with the manual locking option) and a manual tranfer case.

 

Help me out here; I dont know what DMM stands for.

Anyway, I checked the fuse. Good.
I checked for voltage at the switch. Good.
I pulled the switch apart and checked the condition of the contacts. Good.
I guess I'll check the connection at the T-case next.

And about the manual vs automatic debate, I am willing to put up with a few bugs in exchange for all of the modern conveniences. I love the luxury!

 

DMM = Digital Multi-Meter. Checks for voltage.

Did you hear the motor trying to engage at the T-case when you flipped the switch? It might run a few times before it engages.

 

No. No clicks or anything.

 

First, I'm assuming that the 4x4 light on the dash didn't come on?

OK, there's a bunch of stuff to do. First and foremost, pull the connector for the servo motor on the transfer case and check for voltage there when you FIRST turn the switch to 4x4. Use a test-light, it's probably the easiest to deal with. Connect the test light to the two wires in the connector, don't bother going from one of the wires to ground.

If there is voltage there, but you don't hear anything from the servo when it's connected, the servo motor is bad.

If there's no voltage there, we need to go further. Report back and we'll work through this.

 

If you didn't hear anything it means either you are not getting voltage at the T-case motor or the motor is bad. I was tinkering around under my truck one day and found the connector to it had come loose and was barely plugged in.

 

Thanks for the tips, but I'll have to put the T-case problem on the back burner, because the wife just called and told me that the starter is not doing anything today! (When she turns the key to the "start" position, it doesnt even click.) I'm going to have to get that sorted out first.

Crummy gremlins.

 

OK! That was a long hiatus. The last few months of 2008 were pretty rough, finance-wise, so the truck was parked. We're back in the saddle again, but I've been busy as ever, so the 4x4 problem has taken a back burner until today.

Here's the update: I checked for voltage at the switch, OK. I opened the window, switched to 4HI, nothing. No sounds from under the truck. I opened the hood and tried again, nothing. No clicks from under the hood where I read the transfer case relay is located.

Where are the relays located so I can test them?

Also, where can I find a schematic for the ESOF system?

 

Reread Krewats post, and follow that. If you don't find voltage at the solenoid, then you need to look upstream, but it seems the solenoid is often the problem here...

-Dave

 

Right, but I need to know where the solenoid is. If I could find a schematic, I'm sure I can figure this out. Thanks.