No 4 wheel drive, HELP!!!

O.K., 95 EB, never a problem w/ 4 wheel drive. Today, first snow storm of the year ( it figures), I switched the selector from 2WD to 4Auto. The light came on and stayed on, however, no 4 wheel drive. Just the rear wheels spinning like crazy. I switched to 4Low, same thing, rear tires spinnig like mad. I figured if the 4wheel light came on and didn't flash, it was O.K. The front diff. definitely isn't connecting. I did a quick visual, nothing appears to be un-plugged. Where do I start? 14" inches of snow and no go aint' cool, Thanks!!

I went out and started the Ex., in 2WD I can turn the front driveshaft by hand. In 4Auto, I can't turn the shaft by hand, nor can I turn it in 4Low. I would guess this means the coupler is working, so, why no 4x4? Granted, I didn't have the front end on stands, I'm in the middle of a blizzard as we speak,lol.

Please help!!! No 4x4, findings inside

O.K., I'm in the middle of a blizzard last night, switch to 4Auto, light comes on, no 4x4. I switch to 4Low, again, light stays on, no 4x4. So I rush inside and read all these posts. I couldn't put the Ex on stands, however, when in park and running, in 2WD I can reach the front D-shaft and turn it by hand. When in park and running, either in 4Auto or 4Low, light stays on and I can't turn the shaft by hand. Back to 2WD, I can turn it. So it appears the Center connect is working, yes? Where do I start? Thanks!!!!!!

O.K., what do I look for , and, is this a DIY or big $$$$$$?

Center Axle Disconnect. It's not locking the front axle. It could be a sticky CAD, broken or leaking vacuum line, or sticky or non-responsive vacuum solenoids.

Incidentally, I've got the exact same issue with my F150 today... Of course, it's stuck in a snow pile at the moment...

Thanks, when it stops snowing I will check the vac. lines. If it is a sticky solenoid, how do I diagnose it and what is the fix? Thanks

You'll have to pop the cover off the axle disconnect and take a look. Could be a vacuum line problem, leaky diaphragm in the disconnect, stuck solenoid, etc.

Here's a writeup I did on how to control it manually. Not exactly what you need, but it has a pix of the solenoid and some descriptions on operation. http://www.explorerforum.com/forums/showthread.php?t=88718.

Here's a pix of the front axle. The vacuum actuator is just inboard of the left cv joint (kinda behind the hub in the pix). If that actuator is leaking or cracked, it won't work either.

Update: Second snowstorm and I still haven't had time to crawl under the Ex. However, I was thinking and remembered: about two months ago I replaced all the upper and lower Ball joints, etc., including the inner pass. CV axle boot. Naturally, I had to take out the CV axle, a little tug and out it came. Replaced the boot and pushed the axle in, everything went fine. Could I have messed something up pulling out and putting the axle back in?

I need to look at a disassembled CAD. I'm wondering if a shift collar could have fallen off when you had the axle out. Is there enough room for that to happen...etc. I'm still thinking vacuum supply or motor though.

O.K., any help greatly appreciated!! When the temp. gets above 25, I'll crawl around and try following the vac. lines and look at the wiring. Again, it must be simple because I rarely use the 4x4, only when snow, and it worked fine last year. The only diff. was in removing the CV axle.

not to resurect an old thread but, did you ever figure it out? im havin the same prob this year