1998 4X4 got stuck in 4WD-Low
My son's 98, 3.0 Vulcan, 5speed, 4x4 got stuck in 4wd-low this past weekend. Attempts to switch back to 2wd or even 4wd high failed. After several attempts the system's indicator lights started flashing both 4wd-high, and 4wd-low.
Read all of the threads found here and on other boards. Checked the usual culprits fuses (both in cab and one under hood), shift motor, cables, vacuum lines, power etc. Cannot get the shift motor to turn when connected to the system. Suspect possible issue with the control module or the position sensor in the shift motor assembly.
We pulled the motor and was able to manually shift the transfer case back to 2wd-high & also pulled the vacuum lines to the front hubs to ensure those disengaged as well. Applied 12 volts to the motor and ran it to align the drive mechanism to the transfer case shift rod & re-installed the motor to keep the shift lever in place (left cable un-plugged). Drives fine in 2wd now, without 4wd. System will flash the lights every so often but has no other obvious affect on drive-ability in 2wd.
QUESTION - can we leave the 4x4 disabled in this manner indefinitely and drive the truck until more time is available to troubleshoot/purchase the parts necessary?
- Manually shifted transfer case (wrench on shift rod, pointed to 2wd marking on casting)
- Shift motor turned back manually to 2WD-High, re-installed on transfer case
- Disconnected shift motor cable & electric clutch wire (brown)
- Disconnected modulated front hub vacuum lines (plugged ends)