Weird problem with 4wd

Hello everyone.. I've been a member for a while but it's been a long time since I've logged in. I had a hard time remembering my password and trying to reset it, but somehow I'm back.
I have more questions about my 3.0, 1998 ranger, 4wd, manual transmission. I should first mention that I replaced the factory pulse vacuum hubs and cv axles so I have live front axles now. I've done quite a bit of work to it so far, including a limited slip differential swap, which it works great.. There ain't many pieces left I haven't replaced since I bought it almost 2 years ago, but..... I've been having a hard time keeping the 4wd working.

So far I've replaced shift motors and the 4wd ECM thingy, or whatever it's called ( the little thing behind the radio towards the left with wires going to it) twice... It seems to work great for about a week then I hear that abnormal click sound a few times behind the radio then the 4wd lights start flashing and 4wd is gone.
I found out if I take the radio out, unplug that relay thing and plug it back in the 4wd starts working again, but it doesn't take long before it quits. I got 2 used and 1 new shift motors which I bench tested and they all seem to work the way they should, so I'm leaning towards an electrical problem, but I'm lost by now. All fuses and relays are good, it seems like it does it whenever it wants to for no reason.
I'm very mechanically inclined but when it comes to electrical I'm not too handy.
One more thing, nothing related to the original question but I noticed a "water in fuel" light come on today too, I've never seen that in a ranger, it's like a gas pump with rain drops, I thought that was only for diesel vehicles. Has anyone seen this before? I just thought I'd let you know just in case someone has an idea of why it showed up on the cluster.
I'm hoping someone could guide me in the right direction or have someone advice or suggestions. Criticism is welcome as well. Thank you guys in advance...

Yes, you are correct "Water in Fuel" light would only be on diesel models, there is a sensor at the bottom of fuel filter that detects water buildup, water is heavier than gas or diesel.
Any instrument cluster may have that icon but bulb or wiring for it shouldn't be there on gasoline models
It is odd
Many of the dash warning lights get 12volts with key on, and are grounded for "bulb test", then ground is removed and lights go out until grounded by sensor or computer to indicate a problem.
This reduces the amount of 12volt wiring that is needed, so most wires are Grounds, if a wire shorts to ground then all that happens is that the light comes on, no blown fuses.
But light is on, so needs to be investigated


The unit behind the Radio is the GEM, generic electronic module
It runs most of the cab electrics, i.e. when you turn on the wiper switch it doesn't connect to wipers directly, wiper switch goes to GEM, when you activate wipers, GEM gets that signal then activates wiper relay.
Same for dome light, wires for switch in the door goes to GEM, GEM activates the dome light.
Door ajar
door locks
power windows
If it is in the cab and electric then GEM controls it

And in 1998 it also controls the 4WD

There are 4 parts to 4WD control in 1998
Switch on dash
GEM
Motor relay box
Shift motor

Switch on the dash tells GEM what Driver wants
GEM then activates the Motor Relays, just 2 relays in a separate box, works like Power windows do, 12v/ground turns shift motor clockwise, ground/12v turns motor counter-clockwise, so the 2 relays Reverse polarity to the motor to turn shift rod to correct position.

Shift motor has the 2 wires for power that go to Motor Relay box(box is often under glove box or in passenger side kick panel)
Shift motor also has 4 to 5 "position" wires that go to the GEM
These wires connect to spring contacts that "read" a wheel in the shift motor's gear housing, GEM "knows" what contacts are open and closed for each position of transfer case shift rod
GEM powers motor to move in correct direction until correct contacts are opened and closed.
GEM then activates the dash light for that position
Flashing light means motor didn't move, or contacts are not changing, or GEM is "lost" so won't do any thing.

Pictures here of shift motor and contact wheel: http://www.explorerforum.com/forums/index.php?threads/how-to-rebuild-4x4-shift-motor.123542/


You can get rid of the electric shift if you don't need "shift on the fly".
The shiftster is a handle/knob that bolts to transfer case in place of shift motor.
Up side is 4WD always works

Down side, you have to get under the vehicle to change positions

If you had manual hubs it would make it more appealing, just leave transfer case in 4High year round and lock hubs as needed

The motor relay box is what I was talking about, mine is behind the radio, next to the GEM, to the right of it and below. It's got 10 pins but I think the wire harness that go to it has only 8 wires, not sure though, and they're the same color wires that go to the 4wd shit motor. I'm not sure if I have the one by the kick panel, I've never looked there, but I know in older models it's by the kick panel.
I opened it and there's a small relay looking thing inside, there's a serial or model number or something, F57B-6912-AA. I can't figure out how to upload a picture of it, I'll do it when I figure it out. Is there any other relays related to the 4wd hiding somewhere in this truck? I checked all of them I could find and they all work, including the ones under the dash to the right of the steering column, which I'm not sure what they're for. Everything electrical in this truck works as it should, except for the 4wd, I've been scratching my head trying to figure out what I'm missing, I need to get it fixed before winter, that thing won't go anywhere if we have 3" of snow LoL.
That water in fuel light went away after a while, I understand they might've sold diesel rangers in other countries and might have the same cluster with that light in them, but what surprised me is that mine has the bulb in it and it actually came on. It's the first time I've ever seen something like that, I thought about asking a dealership but they'll probably think I'm stupid LoL.
I'll keep doing some research on the 4wd, if anybody has anything helpful I'll be checking the forum. Thanks..

Fwiw, we're back in business. Have about 75 Shiftsters in stock, ready to go........

Cheers,

Rick

That Relay box should just have 7 wires

I uploaded 1998 GEM and 4WD wiring diagrams awhile back in this thread: http://www.therangerstation.com/forums/showthread.php?t=162915

Ricky B said:

Fwiw, we're back in business. Have about 75 Shiftsters in stock, ready to go........

Cheers,

Rick

Click to expand...

Glad to read that

While I'm not near as educated as "RonD", I do have a 99 4.0, 4x4 5 speed with BW 1354 tcase. Bought it, replaced the vacuum crap with manual locking hubs, and then had the same problem. The clickinw then the blinking. So evertime I wanted 4x4, I'd get out, remove battery terminals and reinstall to reset the truck lol. It worked once then the clicking amd blinking was back. So I ordered a rebuilt shifter motor (stock BW motor rebuilt by cardone; amazon) and got even more clicking and blinking. My next stop was the GEM but I for some reason couldn't convince myself of that being the problem due the fact that the motor was getting the signal, it just wasn't stopping when it was supposed to or didn't wanna move at all. I'm not sure. So I decided to get a new shifter motor and BAM. Like new. Very ironic that the new shifter motor was a cardone too but I got it from my loval parts store a few months ago and haven't had the slightest bit of issues yet. I guess it was just a bad part. The first time.

Sent from my SM-G900V using Tapatalk

Mhh. I've tried 2 different shift motors and both did the same thing. After talking them off and putting them back so many times I managed to strip one of the threads in the the transfer case. Luckily I still had a little bit of threads left and was able to put a longer bolt in it without having to tap new thread.
I have 2 motors besides the one in the truck, I'm tempted to open them and see if there's something broke inside, like that little stupid plastic stopper thing.
By the way, what's the brown wire going to the transfer case for???

A little update you guys. Today I had to drive on gravel roads for a while, so I decided to try 4wd again, expecting nothing. Well, I turned the knob to 4hi doing around 40 mph and the goddamn thing actually engaged... I even stopped and hammered on it to make sure I wasn't just dreaming and yes, it was working. I tried that several times, from 4hi to 2wd back and forth for about 5 miles till I hit pavement and put it back to 2wd, it worked like normal every time.
I don't know what to think about it, it's just weird. I'm gonna try it without the truck moving and see what happens. But I think 4hi should engage whether you're moving or not right???

Yes, 2wd, 4hi, and 4low are available when stopped, and you should do that shift once a month, don't have to move, keeps shift motor brushes clean and lube on gears spread around

Most likely wiring issue if it works now, loose connector

I seem to recall you also have to have the clutch depressed to make the shift in or out of 4-LO (or if automatic, needs to be in Neutral). Possibly stepping on the brake as well, not sure (been awhile since I've used the e-shift system).

Electrical gremlins can be a pain for sure. Can't hurt to unplug each connector related to the 4WD and check each contact for corrosion, then reassemble with some dielectric grease.

Reminds me of a buddy who had an intermittent stalling problem on his Toyota... Had it into the dealer numerous times, they could never find it. One day it died while idling while I was standing right there, so we wiggled things (trying to restart it each time)... After it finally started, we pulled apart the last connector we wiggled (ignition module connector). Sure enough, corrosion on one of the contacts. A little cleaning, some grease, and it was fine for the next 5-6 years until he sold it).

Well just for the heck of it, it took all the wire harness apart, sprayed them with electrical parts cleaner and put some dielectric grease on every connector. So far it's still working, I don't know for how long though.
I'll keep trying it and keep posting if something weird happens. I'm still gonna open one or both of the shit motors and see what might be wrong with them, I just need to buy a set of tamper proof bits.
Thanks everyone for the help, I'll keep you posted.

Thanks for the update

Hey guys I'm back. I've been playing with the 4wd for about 1 week, on gravel, mud, dirt etc. trying 4hi and 4lo and so far so good. It works really nice with the limited slip I put in it. One thing I noticed is that vent hose coming out of the axle tube broke off and was leaking a little bit. When I got home I unscrewed the fitting, it was weird that it was so loose, I didn't even need a wrench to get it off, that's when I noticed it wasn't leaking from the hole in the fitting but around the threads. The hole was plugged up with rust and dirt so I used a small drill bit to open it, put some teflon tape on the threads, a new piece of fuel hose and looped it up on the frame.
I've heard it can start leaking out of the seals if it doesn't have a vent to relieve the pressure, what else could've happened if I wouldn't noticed it and fix it??
Thanks everyone for all the help..

Sorry to be a pain in the ass, but does anyone know yet what the brown wire going to the t-case does?
My friend just wrecked his ranger and it has a manual shift t-case, but his truck is way newer than mine, I think he said 2004 but don't quote me yet. I'm thinking about buying it from him but I don't know if they put them manual t-case on a 2000+ ranger. If all true, can I still use it for my 98 or should I pass? He says it will fit but I want to know before I hand him any moneys. His is a 4.0 litre manual. Please let me know to the best of your knowledge. Thanks everyone...