intermittent ABS light

Hi all.. i'm kinda new hear.. i did a search for my ABS problem but found nothing that could help. So i bring this question to anyone who may be able to help. It's on a 96 jimmy. the ABS light will come on from time to time. i took it to my mechanic and he says that it is the right front wheel speed sensor. he tested the sensor itself and the wiring to wherever it goes and found nothing wrong. has anyone ever had to deal with this before. i dont want to take it to the a dealership if i don't have to. even some general ideas or tests would be great.
thanks in advance
layta

i believe there was a recall about a wire shortng at the right rear(Passenger side) of the engine A wire was pinched between engine and fire wall. If I remember right

water was getting up and in the sensor and shorting it out.