Originally Posted by sky_blazer

If the front actuator needs to be replaced there would not be vacuum pulling the cable to engage the front differential. If your problem is the front engagement of the differential then I would suspect the switch before the actuator. Also does your 4x4 work when you turn it on? If so then your actuator should be working and it's the switch. I think you can find them at AutoZone or dealer can't remember part number

Originally Posted by sky_blazer

Try this, turn engine on, engage 4hi, get a jack and jack up passenger side front wheel, try to spin wheel, if it spins a little then locks the 4x4
is working. If it just spins and spins the front actuator did not lock the front differential in