The motor for the ABS keeps running

Hi Cecily,
There are several parts to a blazer 4x4.
First is the transfer case,When you push the button for four wheel, can you hear you it locking up,by pushing the buttons from 4x2 to 4x4 ?
If you here a slight clunking sounds its working. Next Blazers now have to lock in the front wheels. This is done by a vacuum assist. There is a vacuum line from the engine that runs over and under the battery.If it looks like it is attached at the engine, The next part is harder. You need to remove the battery to expose the servo valve that the vacuum is suppose to work.You can start the engine before taking the battery out, it will stay running. Pull the vacuum off the servo to see if its moving.if not replace it. if it is moving, there is a small relay mounted on the fire wall in the center of the fire wall, replace it.

2001 does not utilize vacuum to engage the front axel. A cable is used. There are a few conditions that can cause this. The most likely is the encoder motor. It's best to have the vehicle scanned. The TCCM is located behind the right kick panel, sometimes if it's unplugged and plugged back in, it will begin to work again.

you will probably have a few sensors where the plugs might be different but other than that you should be able to

will work might have a few sensors with different plugs but shouldnt be to bad

There's been a lot of problems with the 4wd systems on the blazers of that vintage. The only sure way to track down the cause is to have the system scanned. Some of the most commom causes are: the switch in the dash, - the control module, - the transfer case . There are other issues if it has auto 4wd as the ABS system is tied into that system to activate it when the sensors sense wheel slippage. If your blazer has the auto 4wd funtion and has a ABS light on, it could be in the ABS system.
IF you could get it back into 2wd, you could pull the fuse to the 4wd to dis-able untill you have a chance to have it scanned.

Questions and Answers Chevy Blazer 4WD Shifting Problem
Q. I have a 1994 Chevy T10 Blazer 4x4 with the 2.8 liter V-6 Vortex engine with an automatic transmission. When I go to engage the 4hi or 4lo, the lights on the switch flash and I can here the transfer case engage and then immediately disengage. Is this a vacuum problem? I found the relay switch box under the dash and disconnected it then reconnected it.

Sometimes this works, sometimes it doesn't. The other day someone told me the vacuum actuator is located under the battery. As soon as I removed the battery bracket, battery still connected, The switch worked and the 4h/4l worked, I tightened up the battery bracket and all of a sudden it stopped working again.

I repeated the above steps and everything is working properly for now! Any ideas as to what might be causing this?
Thank You...
A. I'll try to explain how this system works for you. When you push a button, the signal goes to the Transfer Case Control Module (TCCM), a small metal box under the dash. In turn, it sends a command to the encoder motor which is mounted on the side of transfer case.

On a working unit, the transfer case will shift to the selected range. This will cause an internal movement of the linkage which pushes up on the ball of the vacuum switch. The vacuum switch has 3 hoses to it. One is the supply from manifold vacuum, one is the feed that goes to the actuator under the battery. The other is to drain off the vacuum when it's taken out of 4x4.

There should be DTC's stored if you can't get it to shift. These are read by jumping 2 wires in the ALDL plug under dash. All codes will have you check for 5 volts at the encoder motor plug on the 4 terminals. I have had this trouble in the past and fixed a few by running a new ground wire to the encoder terminal that is ground. I don't have a schematic handy so I can't help you there.

Unplug the TCCM, try tapping on the encoder motor and re-install the plug after it's been unplugged for at least 2 minutes. Cycle the ignition on and off 5 times, then on. Now try to make a shift.

I have seen ruptured servos under the battery. Battery acid leaking down and eating into the servo cable that runs to the front axle making it too stiff to move the cable. If the switch light changes from 2 to 4h, the TCCM and encoder should be okay and the problem is most likely in the vacuum switch or servo area.

try pulling the fuse for the 4wd and see if it needs replacement if not leave it out for a few minutes before replacing it as this will allow it to reset .

also check all the vacuum lines and especially
" dry-rotted " ones replace and re-connect if disconnected as well as any missing connections

yes its at the rear of trans

air line from under battery to fire wall falls to bits

Check your codes in the onboard computer