i have a 1998 jeep cherokee 4.0L with the v6 engine in there. now whats going on is my abs light doesnt come on at all (even when first starting up the car) now will this cause a problem to my brake system. which brings me to my next question. when i apply the brakes to my car the brake pedal vibrates. (skips) there is plenty of pad left on my brakes and the steerting wheel doesnt vibrate at all. and my 4wd drive light doesnt come on when i have my 4wd activated is there a fuse or a sensor i should look for to replace this. (along with the abs)