I have searched the forum, looked at diagrams looked at 15 different part stores (online) and I cannot determine the location of the rear wheel abs sensor(s). Now before you all say "what a moron" I pulled the original 10 bolt axle assembly out and there were no sensors on it. No sensor rings on the axles and no wires going to the axle or anywhere nearby. Got a used axle from a 92 with 4wal (wrecked with 67k on it) and verified the blazer was 4wal there are no sensors in it on it or near it. Alldata says there are 2, one at each wheel all the other harness data I can find says one at each wheel. Online parts stores and 2 real stores have a single sensor with pipe thread fiiting like it screws into the pumpkin. Where the heck is this thing or things.

 

The rear axle speed is monitored through the main VSS (vehicle speed sensor) located in the back of the transmission (if 2wd) or transfer case (if 4wd). By comparison of the output of the VSS to the front WSS (wheel speed sensor), the EHCU (electro-hydraulic control unit) can determine if a rear wheel has locked up and can modulate (pulse) the pressure to the rear wheel cylinders.

 

Thank you very much. This is extremely helpfull.