So my 1999 D1 transfer case will shift from Hi to LO but it won't lock. It moves but won't go all the way into "lock" and dash light doesn't go on when it is in locked position. Shifts easily from Hi to Lo and back, Am I looking at a linkage issue? or something inside??

Haven't crawled under yet.

 

The light can be 'lazy'. It may take a few turns of the wheels to illuminate.

Obviously, if you do move forward keep the steering wheel straight or make sure you are on a surface where the tires can slip (gravel, dirt, snow, etc)

 

Actually I think the CDL will engage easier if you are moving and turn the steering wheel slightly back and forth.

 

It is sitting in the grass but I didn't try driving I'll try it again.

Thanks.