no low range in my 91 mighty max 4x4

i am having a problem with my low range in 4 wheel drive... the high range works fine but when you shift into low range it will not engage the front wheels... was working fine on the trail then just quit... i do not hear anything cracking or poping... is there some sort of electrical wiring or vacuum i could have pulled loose??? need some help!
1991 mighty max 4x4 with 3.0 and manual 5 speed

Check to see if there is anythang in the way of the shifter maybe a rock or sumthin is stuck in the way