Hey, I'm writing to you from Vancouver Island on the West Coast of Canada. On a good day, I can see Mount Baker in the State of Washington over the Strait of Georgia. I recently bought a 1993 4X4 extracab 4L automatic with 160,000 miles including a box liner for CA$600 bucks. (That's US$450.) Thought it was a decent buy. Body is clean, clean. runs very well, but the 4x4 won't engage. I'm hoping it will be something simple. Might be the transfer case controller, or electrical connections perhaps. Here's a photo. The far wheel is off as I'm checking the brakes, and all are decent. Yeah, I gotta get the mustang back on the road too! Later, eh?

 

Welcome to the forum

Good buy, my 1994 4.0l 4x4 has over 400k now and still going on original engine and manual trans

There are 4 parts to the 1993 4x4 system
The dash switch, rarely fails unless buttons are physically broken
The 4x4 controller, behind driver seat, under jump seat or behind plastic panel, looks like an amplifier, these can go bad but not a common issue
The transfer case shift motor, these can wear out, or get dirty from not being used monthly
The automatic hubs, these tend to last but can be over lubed, when doing the wheel bearings people often put too much thick grease on them so they can't move to lock and unlock the axle and hub, just a light coat of 30w oil is what they need

Fuses are the first thing to check
In the cab fuse box check #7 should be 15amp fuse, this powers the switch and the 4x4 controller
Then in the engine fuse box check ELEC. SHIFT fuse, 20amps, this is for shift motor

Here is a diagnostic article for 1994 and earlier 4x4 system: https://www.therangerstation.com/tec...is-1994-older/
This deals with the electrical side

Here is an article on shift motor rebuild: https://www.therangerstation.com/tec...e-shift-motor/
Once you have a working 4x4 system you should shift it from 2WD to 4high and then to 4low and then back to 2WD once a month, just sitting in the driveway waiting for engine to warm up, or just after you get home , you don't need to drive it in 4WD, all you are trying to do is to keep the shift motors brushes clean, and the contacts, and the lube in the worm drive spread out
Leaving the 4x4 system unused for 11 months a year does more damage than using it daily, lol, so once a month, and then it will work when you actually needed it

If your 4x4 lights are coming on but no 4WD then could be auto hub issue, but this is last on the list, you need to get transfer case to shift first
The Auto Hubs work by axle torque
In 4WD the front driveshaft will turn when vehicle moves, in 2WD it doesn't move, so the movement of the front driveshaft and axles causes the auto hubs to lock axle to hub on both sides, and they will stay locked until torque from driveshaft/axles is removed
When you switch back to 2WD it will take a few seconds for Auto hubs to unlock, and sometimes they don't, try backing up 50ft or so and they will unlock

There are no repair parts anymore for these Auto hubs, just too old, even wrecking yards are picked clean, but you can still find Manual hubs so can convert them to manual lock/unlock hubs

 

Wow! Thanks do much for all that info! I will follow through with that in a bit. Right now, I am trying yo get the instrument cluster out. Following university of YouTube, I've gotten to the point where I'm now trying to disconnect the speedometer from the back. Its way up and in there. Not sure what the process is to release that. There are only a couple of dash lamps working, so I'm trying to work on the few things that are safety related first. I've isolated the shift indicator, and the cluster is loose, but not sure how the spedo is released. I'm sure its something simple, but I dont want to break anything
I couldn't find anything on the YouTube regarding THAT part of the removal. Any suggestions?
Thanks!
Mike

 

Real short video on Ford speedo cable release here:

 

Hey Ron,
Thanks for the video.....I did finally figure it out. I had found enough Youtube videos, that together I was able to sort of get an idea of what I was trying to find behind that cluster that wouldn't move! I have a small remote camera on a 3foot flex shaft that I was able to slide in over the top of the cluster to see the "white tab clip" on the top of the cable connection. I did go under the truck and loosen a spring clamp securing the spedo cable to the frame. That allowed me to gain about an inch of additional length to push through the firewall. I was then able to actually get my big hand over the top of the cluster and find the clip. I managed to push it down and get a release from the spedo head. I had to keep from pulling the cluster towards me because it would put pressure on the clip, and not release. as soon as I was able to push the spedo head back in and push down, it let go. Thankfully! I changed all 17 bulbs, and had the replacement work done in about a half hour. I really should make a video on this technique, as I couldn't find one any where. Yes there are some that show the clip release like the one you had sent me, and some others like it, but none say "This is how you get to release it from the dash!" So all is bright and shiny on the dash now, just like new. Now, I'm waiting for replacement headlights and turn signals all around from Rock Auto. They're the cheapest I've found online even with the US dollar exchange. Crazy! I'm not buying the aftermarket HIDs or LED Projectors and the like. I did all that with my Mustang, (Spec D stuff) and sure they look great, but they were finnicky and did not provide great performance in lighting the road ahead. I don't have the time or the budget for playing with it all to make it work. Just factory style replacements will do for me. they will improve the look, ( no very yellow headlights) and light the road better. I may get a 24 inch LED bar to fit in the grill as I drive on rural roads quite a bit. Any suggestions that don't cost as much as I paid for the truck? When I get the time, I'll be checking into the 4x4 control module and motor and such to see how I can get the 4x4 to engage. A project for another day. Too many other things in life command my attention! ​​​​​​​
Anyways, Thanks again!
Mike

 

Good work

Thanks for the update