Ok so after doing some research, I cant find any help. I went out today and took my battery and tray out, hooked the battery up thru the jumper cables and started the blazer back up. I had a friend hit the 4wd and I watched the actuator. The actuator works like normal, but still no 4wd. It pulls the cable and everything. This is my first IFS 4wd. I dont know how it works after the cable. Anyone else have any idea as to what it could be?

 

Are you getting a service 4x light? Switch on dash flashing?
Did you look at the encodee motor on transfer case to see if that is engaging? It is on driverside of transfer case by front drive shaft...see if that is working. You can do a search to check pics so you know what you are looking at.

 

Vacuum lines and transfer case oil level, maybe?
Just 2 of the things that were wrong when mine wouldn't shift

ETA - No "service 4wd" lights for those, at least in my case

 

The transfer case is working too. You can hear it engaging like normal. Even in 4LO the front tires arent kicking in.

 

1st off what are you driving ? how many buttons do you have in the cab ?

DO you hear any clicking in the cab when pushing the 4wd buttons ?
DO you hear the transfer case trying to shift into a 4wd mode ?

this information matters if not posted its going to be harder for members to help you

 

X2 on providing more information.

 

Sorry guys. I wasnt thinking. Its a 97 Blazer. It does have the 98+ interior. Its got 3 buttons for the 4wd. I can hear clicking inside the cab plus I can hear/feel the transfer case engage.

 

I dont see what the issue is...unless i missed it in your posts..you said its engaging 4lo...and the axle is engaging...so whats the issue? I am missing something here.

 

The front end isnt engaging. The transfer case locks and the actuator under the hood works perfect. The cable that runs to the front diff is NOT broken. It pulls like it should But the front still is not locking.

 

here this might help: common 4x4 problems

To me it sounds like something after the cable. Something can get out of alignment, i dont remember what exactly but i have read about it a few times on here. I think its covered in the link i gave you.

Edit: Does the actuator pull the cable 1/2-3/4 of an inch? if it pulls the cable more than that then theres something out of alignment but if it pulls less than that then you have a vacuum problem