I have a 1988 gmc k1500 extended cab. It was a cold day with lots of snow in the driveway. I put my truck in 4x4 but no light came on, tried it a few times to no avail. I tried looking in the fuse box but could not see a fuse for the 4x4. Does any know where the fuse would go for this particular truck? I wouldn't mind a wiring diagram for this truck so I could trace the wire to the TLA just in case if it is not the fuse. The Haynes manual is pretty vague on this problem. I hear there is a cable posi-Lok to replace the TLA,is this the way to go,or what are the negatives if I installed this cable posi-lok? Any help on this would be much apprieciated. Thanks for any help.