ABS Light
 

Sister just bought a 2000 s70. Looks to be in good shape. The abs light is on. Guy she got it from said it came on after he had some work done on the axle. Thinking looking around the wheels would be the best place to start to see why light on. Any suggestion on what to look for and do you think it's the best place to start?

there's an ABS sensor for each wheel - sometimes they can get covered in grease or the dirt could be on the wheel where the sensor is trying to read. You can pull it out to inspect and try and clean the hub to see if it clears. Its also possible the wire got nicked during the repair would may warrant replacing the sensor.

Brake cleaner works very well to clean the wheel speed sensors.

unfortunately - the control unit is the most common item to fail on these models. The fault sometimes indicates a r/r wheel sensor - but its usually the bcm that fails

Thanks. Will give it a look this weekend.

If it does turn out to be the ABS controller, the root cause there is typically cracks in the solder joints on the board. Several shops offer services to restore the boards - including ABS-Midwest, RochaTek and XEModex (who now only wholesales but I believe FCP is one of their retailers).