First off awesome site and glad for all of the info that I have read so far. Now for the question.....I have 2002 F350 CC DRW 4x4 and no action from my 4wheel drive switch. Switched to 4-hi with truck off and can hear no noise also no 4x4 light on dash. I checked all fuses that pertain to 4-wheel drive and all were good. Took switch out dash and checked on volt meter. Only 1 wire has power no matter what I turn the switch to. Is this a bad switch or does this not happen. Thanks for any help

 

Welcome to FTE, not sure what else to check I think the hubs are engaged via two vacuum lines to the axles. May check there.

 

Welcome to FTE

There are a few things that could do this, but we need a bit more information. Do you have ESOF or have the hubs been changed to manual ones?

 

Welcome to FTE.

You said when you tested the switch you had the truck off, did you have the key on? With the key on and truck off, you should hear the motor on the transfer case run.

 

I had no response from my switch when I bought my Ex. I discovered that the little tab that held the wiring harness on the transfer case was broken off amd the harness had come unplugged. A little electrical contact cleaner and some silicone sealant and I was all set. Check the easy things first.

 

x2, start there and by checking fuses and go from there.

 

Im having the same exact problem on mine. IM pretty sure its the switch just need to get my good volt meter from work to conferm my findings before i spend 55 bucks at autozone for a new one.

 

Check the xfer case motor plug first!

 

It is ESOF and the hubs are stock. When I tested the switch the engine was off but key was in run position.....no noise from t-case. Also tested the switch with meter in both key on engine off, and engine on....same results. 1 wire with about 6 or so volts....other 3 no readings no matter what position the switch was in. I had checked the plugs on the t-case and other than a bit dirty they are secure.

 

With ESOF you must be in Drive for the transfer case to engage 4hi. Get someone to sit in the cab, turn the key to run but not start the motor, put the truck in drive, and then flip the switch. Stand outside the cab and listen for the transfer case to attempt to engage. If there is no noise from the case, crawl under the truck and check the wiring harness. Trust me, its free and easy. Do the cheap and easy things first before throwing money blindly at the problem.

 

Thanks Peter, will try that tomorrow and go from there. Have been doing more research on the topic through the searches....what a piece of sh++++ that this esof system is. My prob now gotta deal with it.

 

F2.59 30A Transfer case low to high relay, Transfer case high to low relay. This fuse is for the ESOF relays.

If the fuses are good it could be a relay problem.

Here's part of the wiring diagram showing the ESOF relays in the Auxiliary Relay Box 3. I have no idea where that is. This is from page 10 of the PDF. That page also shows the Four Wheel Drive Control Module.

CLICK FOR PDF 2002 Fuse and Relay Information

Hope this some how helps.

 

Everything that switch controls still works. Checked again with the truck in drive...no noise. Checked selector switch with key on and truck in drive. Still only 1 wire with power about 5.5 volts. When select 4hi it goes to about 2-3 volts, 4lo goes to under 1 volt. All other wires still show nothing. If nothing else then I guess I will actually have to take it to.....dare I say it.....a certified mechanic

 

Those voltages are definitely not enough to operate the shift motor. One thing you can try is to hot wire the shift motor to see if it will run. That will tell you if the motor is good. Sorry but I do not know which pin on the connector you should put that hot lead to. Hopefully someone will chime in who has done this test. I know someone has.