Thanks. Lookiong forward to your findings. I have not had time to mesws with this. Actually I had time on Sunday and forgot about it.
Would I not see the light come on on the dash when I key it on if this were the culprit?
Honestly I cant recall the last time I used the 4x4. Likely the last big snow we had and that was 2 years ago. It seemed to work fine the last time though. Nothing alarming comes to mind.

 

no. you would not see the light, because the only way the light does come on is when it is ENGAGED, The issue you seem to be having is not Engaging..

so. on the ESM, There are two wires i believe. one is sort of like a ground looking wire, the other is a clip.

Remove them both and check for corrosion, missing pins, etc...

if you have any lectro clean or anything like that dont be afraid to spray it in the connecter, let it drip out and it will dry almost like super glue.
plug back in. also look around the clip going back to the harness to see any splices etc... same with on the ESM

will watch thread to see any changes.

 

I'm talking about the lights on the dash that all come on when you first turn the key. I dont see the 4x4 light even then?

 

that is not always the worst thing, check your fuse box, you should have a fuse box under the hood as well. i am not sure the number, the cluster may be acting up. i dont see that being an issue.

when you turn your key to the on position before ignite, and they all come on. your light does not show up at all?

 

this may or may not help

in the event it does not. it will not take but 3 minutes of your time.



Do an instrument cluster actuator test to see if it's the bulb. Super easy to do. With the key off, press and hold the trip meter button. Keep holding it while you turn the key on. Don't start the truck, just turn the key on. Let go of the button and the cluster will go through the diagnostic. All the gauges will swing to varying positions and the indicator lights will turn off and on. If the 4wd light doesn't come on, it's the bulb. If it does come on, it's most likely the sensor

the sensor is on the side of the transfer case i believe


check that and then check back with me. worked on my jeep and from what i have heard it is a common practice on fords as well. may be wrong but it is worth a shot. i will go try it on my truck here in a bit too just for the hell of it

 

If the light on the dash does not come on it is either an electrical problem or above stated, or the shift motor on the transfer case is not working. If the light comes on, and the truck isn't in 4x4 then it is a vacuum/hub problem. You should check the fuses first and go from there!

 

Clay: since you have manual hubs you can do the reverse of the test that was suggested earlier (up in the air etc.). So since it could be the light itself, or, not sure on our xfer case but other Ford's have a switch that "reads" what position the xfer case is in. This would be easy to try:

Make sure your fronts are unlocked. Then have a helper engage 4H on the dash and slowly drive forward -- does the front drive shaft turn? If it does it could be the switch in the xfer case (sorry again for not knowing for certain if our SuperDuties have 'em); or it could be the dash light.

A friend of mine bought an F150 and we tested the lmited slip and 4x4 function by taking it into gravel and seeing if we got both rears to spin, and then both them an 1 front in 4x4. Her's has the full vacuum set-up and all tested fine when she bought it... (on edit) So you could also try that in gravel...

Good luck!

 

Thats correct. No 4x4 light when I key on.

 

I learn something new everyday!
I'll give that a shot. I cant even remember where on the cluster the 4x4 light is to look fr it?

 

I had the truck in the air, I locked in the hubs and engaged the 4x4 switch. The front axels turned freely without the front driveshaft turning. Does that tell us anything?
To me that means the TC isnt engaging.

 

you know i cant remember either, what year do you have?

i will search to see if i can find it

anything new?

if your front driveshaft is not spinning when engaged. it is definitally the transfer case. like i said, could be a solenoid. check that first. if that isnt the case then, i would rather let someone be the bearer of the " Bad news"

although.. it honestly is not an expensive fix. considering....

its all just more of a hassle.

if you have a friendly mechanic, or heck... your best bet... to be a cheap as$ like me...

is to go to a dealership, tell them your problem, tell them insurance/warranty will pay for it, but you have to get them a quote. once they figure out what is wrong etc... walk out the door with the answer to your problem, for FREE. and do it yourself or what not.

has worked for me before. dont see why not.

if it doesnt, it is a really hard diag to figure that out. try everything i have told you, and that will rule everything out EXCEPT the transfer case itself. if it is indeed one of the issues i have told you. you are looking at no more then 300 in shop price to be fixed. transfer case really isnt all that much either. im just more inclined to it being something else.

 

I do all my own wrenching. I have lifted the cab and swapped a now long block in so I can fix this silly 4x4, just trying to make sure I educate myself as much as possible before I dive in.
I'll have time this weekend if not before to put er on the lift and start trying these tips you all have given me.
Thanks again! Reps sent...

 

thanks man, wish i could tell ya the exact issue, but unfortunately it just isn't that simple. if you wrench, then its not much of an issue, check everything out, then dial in on your consistent factors. all the while keep testing. one wire in these damned computer vehicles anymore can mess everything up.

i will keep up on thread, as well as do some research and call around to see if i cant get you a bit more info.

 

Hey Clay the bulb for the 4 x 4 is on the left side of the cluster about 2/3 of the way up. Still nothing with mine either. I have no power at my switch on the dash and no power at the actuator, I've checked the fuzes and those are all fine I'm thinking or hoping its the darn relays but i know it's not that simple. Good luck. Eric

 

I suspect my relay for some reason. It's supposedly on the drivers side firewall?