While i had my dash off when i was removing my cd player for replacement i realized that the diff switch was not even hooked up. ealry i had thought my diff lock was not functioning right and this verified this. of course i hooked the switch up and in my driveway today i wanted to test them. i put the truck in neutral and then locked both front and rear diffs. didnt really hear much but then put it in low. i went toward a small 2-3 foot snow hill and didnt even make it up on it. about 3/4 the way up my rear drivers side tire started spinning as if not even locked. i noticed that both lights on the dash were flashing. how can i tell if the diff lock is functioning right b/c it sure felt as if they werent. thanks