The transfer case on my 2001 F250 Powerstroke will not engage when the ESOF is switched to 4hi or 4lo. I checked the fuses and they are good. I removed the electric motor on the side of the transfer case and while it was hanging down with the two plugs attached I did not see any movement when the dash switch was moved to the 4hi position. I used a wrench to manually shift the transfer case and still did not get the transfer case to engage. What next?

 

Replace the shift motor. I bet works then.

 

any idea why the transfer case would not engage when I manually shifted it?

 

Maybe cause you weren't moving so the gears wouldn't mesh by hand?

 

sounds like a shift motor to me, my 4x4 wont engage unless it rolls a foot or 2 so id say thats why you cant shift it by hand

 

Did you put a meter on the connector that goes to the transfer case motor to see if any voltage is there when you switch to 4h?

 

I did use a meter to test the two wire plug. I am assuming that is the power plug. I got voltage but it was spotty. I just figured that I was not getting a good ground on the frame under the truck. If I saw any voltage at all I figured the switch and wire was good?? I saw 13 and 14 volts flash on the meter two different times, but I had to work with the ground to get it register any voltage. So there were times that I moved the switch and did not see any voltage on the meter.

I installed a new shift motor tonight. Had to move the shaft to the 4 hi position again with the wrench so it would align with the new motor. Started the truck and saw the 4X4 light on the dash, drove back and forth in the driveway and never felt the hubs or transfer case lock in, moved the switch to 2wd and the 4X4 light on the dash stayed on. Moved the switch to 4lo (in neutral with the brake applied) and got no change. The 4X4 light stayed on, no low range light and no hubs engaging. Moved the switch back to 2wd and the light on the dash stayed on.

 

Well, I locked the hubs manually while the transfer case was manually shifted into 4hi and I had 4wd. The dash switch still will not engage or disengage the transfer case. When I unlock the hubs manually sometimes the 4wd disengages and sometimes it does not.

I am thinking the switch or wire harness from the dash to the shift motor has a problem and then unrelated, the auto lock hub function is intermitent??

Both hubs (orings, vac hoses, etc) were replaced in the past 10 months. Seems like I should not have vaccum problems with new hubs.

 

The two wire plug to the shift motor is the plug that powers the motor. It does not ground to frame, however. Power is applied in one polarity to move the shift motor one direction, and it is applied in opposite polarity to move the motor the other direction. The 6 wire connector to the transfer case motor is connected to a set of switches that report the motor position back to the 4WD computer.

Take a test light and attach the clip to one pin of the connector and touch the tip to the other pin. With the key in the RUN position, have someone switch from 2WD to 4WD. The test light should flash a number of times. Each flash is the 4WD computer attempting to shift. A shift only lasts about a second, which is why the light only flashes. When the 4WD computer doesn't see that the shift occurred, it tries again a number of times.

If you see flashes on the test light doing this test, it means the dash switch, the 4WD computer and the shift relays are all working. The only thing left is the shift motor and you will need to replace it.

The hub locks are a separate system operated by the same 4WD computer. The computer will not even attempt to lock them until it sees a completed shift. So don't worry about them until you have the transfer case problem fixed. You'll know the trasfer case is working when the 4x4 light goes on and off as it should.

 

So what if it just stays on and no flash when testing 2 pin connector when shifting ?does this mean my 4 wheel computer is f---ed up?