my abs light comes up and im going to check the abs sensors with a multimeter to make sure they are working properly. my question is, how many ohm's and AC V does the abs sensors have to show on the multimeter when turning the wheels.. and does the key have to be on the on position when checking the AC V?

 

Don't know the specifics for your vehicle but in general the ABS Sensor is a Magnetic Pulse Generator.Thia may help some.
All 4 should have a similar OHM reading
AC mv generated by rotation will depend on speed
Air Gap to tone wheel should be around .015-.020"
Tone rings need to be reasonably clean without "klingons" of
rust bridging any teeth
Key off sensor disconnected for testing