4wd up front not engaging

[NDMatt]

Hi- the 4wd works in the rear but is not engaging up front. The forward shaft is turning, but not the wheels. Had the OBD codes checked, and nothing turned up.

Anybody got any ideas on what to check first?

 

[KPT]

Vacuum disconnect. Its on the right side close to where the right halfshaft goes into the housing.

 

[corkey]

couple of things in a 96 that can cause this to happen,
either the vacuum lines for the disconnect are off, which can be checked by changing the heat from defrost to cabin air, if it switches really slow, or if the idle has gotten weird, jumpy, than they are disconnected, crawl under by the passenger side lower control arm and look by where the cv axle goes into the housing, there should be a wire connector and 2 vacuum lines, a blue and a white, put them back into the rubber holder and try it out, if it still doesn't work , reverse the hoses,


next thing that can cause the 4wd not to work is an ABS light, if it is on, than you get the lights on , but no engagement , find out why the abs light is on, and fix it, than the 4wd should work fine, ,

 

[NDMatt]

Thanks, guys- I'll give it a try.

 

[NDMatt]

Lines are good

Checked the vacuum lines and they are connected. Thought we were on to something because the idle does get rough about half the time. But they are connected. What should I check next?