well i guess i'll try one more ........didn't get any takers on the first one

i have a 94 1500 4wd ....i think that the front axle has a heat exchange switch [ for lack of a better name??] to set the the front end......all of a sudden i can't get the front to lock in........the trnsfer is ok.....i think that the little switch on the front axle is shot.......it happened on my last pickup also....but it has been a long time and i'm not sure.......

any help??

don