Front axle not engaging 4X4?

These are thermal actuated and have a two pin connector. When they get cold they don't like to work or one of the return springs is broken, please check the image below to see what I am talking about. Check out the images (Below). Let us know what happens and please upload pictures or videos of the problem.

You need to replace it I sell so many of these things it isn't funny. You did look in the hole to see that nothing was broken inside right. The two wire ones are thermal and the metal around it is cold so it isn't going out all the way this is why it is not engaging. It is -2 here in Idaho so you have it warm LOL.

Wow that usually fixes them. Now do you know if the front drive line is engaged or not? There could be a problem with the shift shaft or the shift fork but that would not be very cheap to fix. That actuator is what turns the light on by closing the switch to indicate that you are in 4x4. I wonder if they are not engaging far enough to lock the front axle. Now this is going to sound really crazy to ask but is the A/C heater fuse good? It sounds nuts but this is the 4x4 fuse too. Have you checked the transfer case switch yet?
Ok the t-case switch is on the left top side of t-case near the shifter area. You will need a test light for this ok. Connect the test light to ground and probe the brown wire (with key on engine off) your test light should light up. If it don't light you need to check the fuse or fix that wire as it is broken or shorted. If it does light up then you need to probe the light blue wire and put it into 4x4 again key on engine off your test light should light up if not replace the t-case switch. If it does light up then get back to me and we go further to check the 4x4 relay ok. Thanks and let me know how it goes.

DO NOT SHIM as this can do damage and if you shim there is only one way to shim and that would make it not be able to engage this is why the actuator extends when you put in 4x4. Now never assume anything as vehicles can act different then you think it should. Now if you jack up the front end and have the 4x4 button pushed and turn the wheels by hand the does the front drive line spin? If so then your transfer case may not be locking in. I would check the transfer case switch as I have instructed and if all that checks out ok. Then you need to check the linkage for proper adjustment so one step at a time here. Let me what you find.

Ok so we have determined that the t-case is engaging this is good this means we need to move to having no power as it should have. You have checked the 25 amp fuse for the 4x4 in the fuse block correct I beleive you said you did. So now we need to figure out why there is no power to that brown wire at the t-case switch connector.
Now there is a convenience center located under the the left side of the instrument panel it has a pink and white wire going into it and a brown wire coming out of it. Yes the brown wire goes to the t-case switch. The pink and white wire is the power to the convience center with the test light connected to a good ground you need to probe this wire and turn key on engine off and see if it lights up. If this pink and white wire has no power then the fuse that it leads to is no good.
Now if all this is ok then you need to put the truck in 4wd and attach the test light to a good ground and probe the light blue wire at the t-case switch and turn key on engine off it should light up if not then t-case switch is bad. The t-case connector must be hooked to the switch as you do this test.
As for the fused you need to check they are location 213 to better explain you have relays on the bottom of it right now the third row up and the from left to right the first three fuses are you 4x4 and rear defroster fuses if equiped if need be use a multi meter set on ohms and check for continuity. Get back to me as to what you find ok.

Ok the one on top was the one to be tested and it tested fine. The one on the rear with two wires is your speedometer sensor to tell the vehicle the speed so if you speedo is working right then all is ok with it and no it won't stop the 4x4 from working.
Ok all signs of the test are pointing to the transfer case relay now. It is under the hood on the right side of the firewall near the battery junction block cover. If you want to verify that you can do a test on the front axle solenoid again you need to have the t-case in the 4x4 position attach the test light between the light blue wire and the black wire if the test light does not light then you need to check the black wire for any brakes if there are not problems found with the black wire then replace the transfer case relay. IF the light lights up then you got a bad axle solenoid and you need to take it back and warranty it. Let me know what you find.

Ok I assume that you mean the one on the t-case. That switch has three as one is ground one is power in and one is power to the front axle actuator.
Yes something can be broke in the front diff. Not always will it make noise even though you would think it should. Get back to me on the relay and we continue Friday. Merry Christmas

Ok with searching all the wiring diagrams available to me I can only find the two wire one for yours no three wire so I can't tell you what all the wires are for on that one. I can't find a pic of the relay but it says it is the T-case relay and that it is located at the right rear of the engine compartment near the battery junction block.