4wd not engaging

[Xlt02steve]

Hi I'm new to the forum. I have a 02 Explorer v6. When the 4wd hi is pressed the light comes on indicating its in 4 high. But it's not engaging. I can get out in a wet field and get stuck easily.if I put it in low, the 4 low light comes on and it changes to the low ratio but again the front wheels won't put power to the ground. I can lift the vehicle off the ground and all 4 wheels spin but the fronts are easily stopped by holding onto them. I know the 4wd shift module is a problem on these vehicles but all I've seen online is the 4wd lights blink or won't come on at all. Mine comes on as if the 4wd was working. Could that still be the problem though?

 

[imp]

Hi I'm new to the forum. I have a 02 Explorer v6. When the 4wd hi is pressed the light comes on indicating its in 4 high. But it's not engaging. I can get out in a wet field and get stuck easily.if I put it in low, the 4 low light . on and it changes to the low ratio but again the front wheels won't put power to the ground. I can lift the vehicle off the ground and all 4 wheels spin but the fronts are easily stopped by holding onto them. I know the 4wd shift module is a problem on these vehicles but all I've seen online is the 4wd lights blink or won't come on at all. Mine comes on as if the 4wd was working. Could that still be the problem though?

More than likely, the "Electronic Clutch" is not engaging. It connects power to the front driveshaft. The 4X4 HIGH light is activated only by the pushbutton on the dash. 4X4 LOW is activated when the shift drive motor completes movement of the "low" mechanism in the transfer case. If that movement is unable to complete, the computer (PCM) will cause the light to flash.

Find from your fuse diagram which fuse feeds power to the Electronic Clutch--- it may be labeled only "4X4". Check to see if the fuse has blown. If the fuse is good, next would be a check of the clutch's coil resistance, done under the truck most easily, at the "brown" wire entering the transfer case. If the coil displays either 0 Ohms, or very high Ohms, it is either shorted to ground, or open circuited. That's the electrical check part. If the coil checks OK, the clutch mechanism may be bound up mechanically, or broken. Determining that condition requires disassembly of the transfer case imp

 

[TechGuru]

If it is not a electrical problem as @imp suggests then most likely the 4x4 clutch is burnt up from a improper tow (usually from a repo that don't give a crap), this is why I never buy vehicles with a repo record, just asking for transfer case and/or transmission problems.

 

[Xlt02steve]

I checked the fuses. They are fine, haven't had a chance to check the brown wire yet. I got the vehicle about a year and a half ago and the 4wd worked great. I didn't use the 4wd until a few weeks ago, when I discovered it don't work. Ill check the electrical asap.

 

[TechGuru]

Has it ever been towed in the time that you've had it? If not, hopefully it's just a loose wire...

 

[Xlt02steve]

Not since I've owned it.

 

[TechGuru]

 

[Phisherman]

I checked the fuses. They are fine, haven't had a chance to check the brown wire yet. I got the vehicle about a year and a half ago and the 4wd worked great. I didn't use the 4wd until a few weeks ago, when I discovered it don't work. Ill check the electrical asap.

I read the older 3rd gens have a 4x4 module behind the glove box which fails sometimes. Hope you get it figured out!

 

[imp]

I read the older 3rd gens have a 4x4 module behind the glove box which fails sometimes. Hope you get it figured out!

Somewhere during 3rd. Gen, the Four Wheel Drive Control Module was eliminated. My '04 ain't got one. The function was incorporated into the PCM. The wiring diagram @TechGuru showed is for 2003, his ride, I'm guessing? Wondering whose diagram that is? The Ford Wiring Diagrams seem easier to follow, though they are printed on 8-1/2 X 11 paper, and "Electronic Shift Control" takes up 3 pages. But, the '04 scheme uses 7 fuses instead of 5!

Interesting that the earlier method had 14 connections to the FWDCM, and 1 to the PCM, my '04 has 14 connections to the PCM. '04 has no ABS connection, but two relays are present underhood R.H. side fender apron which handle the relatively high current demands of the Shift Motor on the T.C. I guess that was incorporated earlier in the FWDCM, which MIGHT have had relays boxed-up in it; I've heard those Modules have been a source of trouble.

I HATE modular boxing-up of mechanical relays, so if one goes bad, ya get to throw away the good ones along with the bad! My '94 Mustang had such a deal, like 4 relays doing PCM Power, Fuel Pump, and electric fan HI and LO, in one sealed box. Bunch of ****! HAD, as I said! imp

 

[TechGuru]

@imp

My 2003 diagrams should be the same for the OP's 2002...

My diagrams come from Mitchell1 OnDemand5.

 

[doug625]

4x4 Module or transfer case motor seem to be the 2 most common causes, or even just a bad ground wire to the transfer case motor

 

[TechGuru]

4x4 Module or transfer case motor seem to be the 2 most common causes, or even just a bad ground wire to the transfer case motor

Transfer case motor has nothing to do with 4X4 HI not working, it is only used to move the gears between high and low...

 

[Xlt02steve]

I just tested the ohms on the brown wire. I get no reading at all from it.

 

[imp]

I just tested the ohms on the brown wire. I get no reading at all from it.

If you are touching your ohmmeter leads between the brown wire (in the connector going into the transfer case) and a good ground (like the case itself), and get "no reading" (meaning very high ohms), the connection at the clutch coil is either broken, or the coil is burned out. imp

 

[TechGuru]

Try measuring between the brown and green.

 

[Xlt02steve]

It also shows no reading with the green and brown wires. Guess I'll have to take the transfer case out and see what' going on inside.

 

[Xlt02steve]

I took the case apart and I didn't see anything wrong. I took the electromagneic ring out and tested it. It gives no reading. I tried running 12 volts to it while in the case and nothing happens. Is there a place to buy this part? I cannot find it anywhere?

 

[imp]

I took the case apart and I didn't see anything wrong. I took the electromagneic ring out and tested it. It gives no reading. I tried running 12 volts to it while in the case and nothing happens. Is there a place to buy this part? I cannot find it anywhere?

Ford BW 1350 Transfer Case W/electric Shift - Clutch Coil Housing -F1TZ7G362A | eBay

 

[Xlt02steve]

I'm needing the coil itself.

 

[TechGuru]

Part number might be 7G361 or F09Z7G361A

Would this work?

Dana Model 28 Transfer Case Magnetic Clutch Assembly F09Z7G361A Ford Aerostar | eBay