YJ 4WD issue

[sodeljeepster]

hey all, i have an 89 YJ and for some reason the 4WD will not engage, the front drive shaft will spin, but the front drive shaft collar will not lock. I know that in the YJ the front axle is locked by a vacuum line, but i cannot find the source of the vacuum. If anyone knows where the source is, it would help alot.

[Muddi1]

There is a conversion to eliminate the vaccum all together, on another forum, I am not sure if I am allowed to post the site name here beings how I am new to this site. I think the cost is less than $100 for a diy set up.

I also have a 92 YJ and I can take a look when it's ligh tout and let you know where my vacumn comes from.