4x4 light

[Bugman123]

When I use the 4wd the light in the instrument panel has a mind of it's own. I am going into 4wd fine but when i first used it, the light wound not go out when i shifted back to 2wd, until i guess it shook whatever sender it has free (Gumed up?). The other day it didn't come on at all when i was in the snow in 4wd. Does anyone have any fixes or test? Thanks for any help. just want it to work the was it is suspose too.:confused2:

Edited December 12, 2009 by Bugman123

[Mopar1973Man]

Hmmm... Do you have the CAD (Center Axle Discconect) axle in the front? Could you update your signature with information about your truck then I can at least look up information concerning your model and year...

[Bugman123]

Don't know what you mean! CAD Let me do some research and see what i got.

Edited December 12, 2009 by Mopar1973Man

[Mopar1973Man]

CAD system is a vacuum operated system on the front axle. There is a vacuum diaphram that pulls/push the locking collar on the axle locking into 4WD or returning to 2WD function. But is common for vacuum line damage to causes issues with CAD axles. Non-CAD axles are locked solid all the time. The Transfer case does the locking and unlocking function.

[Bugman123]

That is what i have. Was under it eairlier todat and saw the the vacuum pod spuns about a 1/4" back and forth. it does not fell loose other the the spin. Is this normal?

[Mopar1973Man]

Sorry no... That vacuum can on the CAD unit should twist or turn at all. More that likely there is a vacuum leak and that why its not pulling to lock or unlock position properly...

[Bugman123]

What am I to do next. Not Good time of year $$. Can the pod be replace or is there a lot more to it?

[Mopar1973Man]

Pulled out my big book... Since I still don't know what year truck I took a guess...:confused:

AXLE SHIFT MOTOR FUNCTIONAL TEST

1. Raise and support the vehicle. Disconnect the vacuum harness from the axle shift motor and connect a vacuum pump to the vacuum shift motor front port. See Fig. 2 .

2. Apply 15 in. Hg (51 kPa) of vacuum to the front port and rotate left front wheel to fully disengage the inner and intermediate axle shafts (i.e., shift to two-wheel drive operation).

3. The shift motor should maintain the vacuum applied to the front port for a minimum of 30 seconds. If the motor does not maintain the vacuum, replace it. If the motor does maintain the vacuum, proceed to the next step.

4. Disconnect the vacuum pump from the vacuum shift motor front port. Connect the vacuum pump to the vacuum shift motor rear port, cap the port for the 4WD indicator lamp switch, apply 15 in. Hg (51 kPa) of vacuum to the rear port.

5. The shift motor should maintain the vacuum applied to the rear port for a minimum of 30 seconds. If the shift motor does not maintain the vacuum, replace it. See AXLE SHIFT MOTOR under REMOVAL & INSTALLATION. If the motor does maintain the vacuum, proceed to the next step.

6. Remove the cap from the port for the 4WD indicator lamp switch. If vacuum was present, the shift motor is functioning normally. If vacuum was not present, go to next step.

7. Apply 15 in. Hg (51 kPa) of vacuum to the shift motor rear port. Rotate the left front wheel as necessary and ensure that the inner and intermediate axle shafts are completely engaged. The axles must be completely engaged (i.e., shifted to 4WD operation) to open the port for the 4WD indicator lamp switch.

8. Determine if vacuum is present at the port for the 4WD indicator lamp switch again. If vacuum was present at the port, the shift motor is functioning normally. If vacuum was not present at the port, replace the shift motor. See AXLE SHIFT MOTOR under REMOVAL & INSTALLATION.

9. Connect the vacuum harness to the shift motor. See VACUUM HOSE ROUTING . Remove the supports and lower the vehicle.

REMOVAL & INSTALLATION - AXLE SHIFT MOTOR

Removal

1. Raise and support the vehicle at a comfortable working height.

2. Disconnect the vacuum and wiring connector from the shift housing.

3. Remove the shift motor housing cover, gasket and shield from the housing.

4. Remove the E-clips from the shift motor housing and shaft. Remove shift motor and shift fork from the housing. See Fig. 6 .

5. Remove the O-ring seal from the shift motor shaft.

6. Clean and inspect all the components. If any component is excessively worn or damaged, it should be replaced.

http://forum.mopar1973man.com/attachment.php?attachmentid=83&stc=1&d=1260655616

Installation

1. Install a replacement O-ring seal on the shift motor shaft. See Fig. 5 .

2. Insert the shift motor shaft through the hole in the housing and shift fork. The shift fork offset should be

toward the differential.

3. Install the E-clips on the shift motor shaft and housing.

4. Install the shift motor housing gasket and cover. Ensure that the shift fork is correctly guided into the shift

collar groove.

5. Install the shift motor housing shield and attaching bolts. Tighten the bolts to 10 ft. lbs. (14 Nm).

[Bugman123]

It has always gone into 4wd but it that the light just would go out after 10 miles or so back in 2wd. The last time it did not come on at all!

[Bugman123]

You got info don't you! Thank You Much for helping me out.

[Mopar1973Man]

Just helps more when I got a yeap and make in the signature... Other than that I got to guess and hope I hit the nail on the head...:ahh:

[Bugman123]

I just add my signature

[Mopar1973Man]

Oh No... :eek::ahh: The information I looked up was a 1990 1st gen... Let me move this over to the 24V 2nd Gen stuff... EDIT: Your lucky! The information goes from 1985 to 2002 for CAD axles...

Edited December 13, 2009 by Mopar1973Man