Domestic SUV

Anyone have an idea what could be wrong (besides the obvious) My 4WD light does not come on but the warning light to service it does which leads me to believe the 2WD is not engaged. I have a 2001 Chevy Blazer. Also the seems to be a “rubbing” noise emanating from the right from while driving

Pls Help

This site helped me troubleshoot the 4wd on my 2001 Blazer. It explains the system a lot better than I can.

At this age the vacuum lines to and from the vacuum switch and the actuator tend to rot and start leaking. The vacuum reservoir is located in the right fender, from there a vacuum line goes to the vacuum switch (center of firewall for Autotrac system) and then on to the actuator (under the battery tray).

If 4wd is not engaged on a regular basis the Transfer Case Control Module (TCCM, right kick panel) will lock up and have to be rebooted/reset. To reboot the TCCM, remove power by disconnecting the battery or the wiring harness at the module.

As for the rubbing noise, does the pitch of the sound change when the steering wheel is turned off-center (i.e. changing lanes)? A change in pitch indicates the front wheel bearings are bad. I had to replace both front hubs on my 2000 Blazer at 66k miles.

Ed B.