Both 4wd and hi/low inoperable; indicator lights inconsistent

[GJarrett]

I am positive my answer is already on this site but I got so many hits in search I cannot narrow it down to find it. Here's what happened:

The last time I switched from "4auto" to "4 low" I did not hear the transfer case clunk into low like I always hear. However after going a few feet it was obvious that it did since I was then in low. I switched to lower my huge boat down a ramp. After spending last weekend on the water we loaded the boat back on the trailer and I noticed that my dash indicator light was not showing that I was in 4low. As I pulled up the ramp, I noticed that my 4wd did not engage my front axle and I was only pulling with the rear axle. Upon leaving the launch area to drive home, the Explorer stayed in 4 low gearing and 2 wheel drive. As I was flipping the 4auto switch back and forth trying to get something to happen, it would sometimes light up that it was in 4 high but never light 4low no matter the position, and sometimes it wouldn't light any indication at all. I had to unbolt the shift motor off the transfer case and use a pair of pliers to manually turn the 4405 transfer case into high range to get home. It never engaged the front axle and went into 4wd at anytime during this.

My understanding is that powering the engagement of the 4wd is separate from that of high/low range shift motor, so I have two problems involving the same wire loom. The brown wire is obviously not sending power to engage the front axle, and at the same time the other wires that are suppose to be sending power to the shift motor bolted to the side of the transfer case are also dead. I was hoping for a blown fuse somewhere but could not find one. I'm not sure if any of the wires going into the side of the transfer case are receiving power. Whatever module it is that the 4auto/4high/4low switch on the dash controls may be toast, or what?

Ideas? Or point me to a thread that already has my answer, since I'm sure there's one in here somewhere

Thanks!

 

[Glen4X4]

You have a full-time live axle where its always locked. And the GEM (generic electronic module) controls the engagement of the shift motor and power to the clutch in the transfer case. So your problem could persist within the GEM its self or the wiring that exits the GEM. You won't always feel your transfer case engaging into high or low gear, I had this issue before where I put into 4low and had no 4wd so to trouble shoot I manually supplied power to the transfer case clutch to make sure the clutch its self was still operable. But to me it sounds like your GEM isn't sending signal to the transfer case or you have bad wires. One way to test that is to take out the radio bezel and remove the 4wd switch from the bezel and hook it back up and take a trouble shooting light and connect it to ground of the truck and then turn your truck on turn the 4wd switch to 4high and touch on the gem where the brown wire comes out of it, its an awkward position but this will tell if the gem is sending power to the transfer case clutch.

 

[GJarrett]

Thanks for the feedback Glen. I was suspecting some sort of GEM problem but didn't want to bias any replies I might have gotten. I haven't had a chance to take out the radio yet to do your test but will next week.

Another thing I've noticed is that on startup, I can hear a few clicks every second or so behind the dashboard in the area of the switch that sounds like it is trying to do something but cannot. After about five clicks or so it stops and won't do it again until the next time I start the engine.

 

[inh]

I'm not going to be much help, but I'd like to say that with a truck as capable and well used as yours, it would be worth it to swap in a manual 1354 transfercase because it sounds like your current one is about dead.

I had similar inconsistent dash lights and 4x4 engagement out in the mojave, right before a piece of the clutch shot out the side of the transfercase and I had to limp home in 2wd with a JB weld patch on the case...

 

[Glen4X4]

Thanks for the feedback Glen. I was suspecting some sort of GEM problem but didn't want to bias any replies I might have gotten. I haven't had a chance to take out the radio yet to do your test but will next week.

Another thing I've noticed is that on startup, I can hear a few clicks every second or so behind the dashboard in the area of the switch that sounds like it is trying to do something but cannot. After about five clicks or so it stops and won't do it again until the next time I start the engine.

Not to sure on what clicking you maybe hearing.....but guess you'll know soon if its your GEM causing the fault. The problems you're having is one reason I've been thinking alot about a manual case swap.