I need a vac line an hose diagram for 98 blazer

First and foremost it depends on the make and model of the vehicle along with what style of 4 wheel drive. Once I have all that I can properly advise you on what to do

Sounds like a bad vacuum line to the IWE ( Integrated Wheel End ) or a problem with the IWE solenoid.
Operationally vacuum holds the IWE ( Integrated Wheel Ends ) out, and once vac is removed the spring engages the IWE.

Start by checking the vacuum line at the IWE for vacuum when the truck is in 2WD mode, and the engine is running. If you have low vacuum on one side, trace the vacuum lines back towards the IWE solenoid.

This is a block diagram of the IWE vacuum lines

while its running,have someone press the buttons on the dash,while you look at the actuator. you should be able to see it working . if not,then follow the vacuum line down to transfer case,and make sure its still connecte,and look at all connections to case and be sure they arent loose. also,make sure the battery tray isnt pinching the lines.

Starting with the vac reservoir behind the battery box, working towards the IWEs, check for cracks in the vac lines and that the check valves are working.

You can place a vac gauge on the IWE vac input, and check to see if it holds vac as a first step. This is the rough outline of the IWE vac components. The IWE without vac will not lock in. Usually the vac lines are the cause of the IWEs not locking into place. Without this, the 4x4 indicator lamps on the cluster will not illuminate ( that is actually a confirm everything is OK, and the status is locked into place ).

Any check engine light on? I would check the TPS or throttle position sensor. Spray some carb and choke cleaner in the throttle body while the car is running. Good luck

Do you have a Vac leak? easy way to find is to let run and open hood.. buy a can of starting fluid.. sprey around the Vac hoses and when the engine RPM picks up you have found your Vac leak.. hope it helps

Try replacing the vacuum lines that go to the transfer case from the engine. I had the same problem on a 95 Jimmy and was told to do it.... I changed every piece of vacuum hose that had anything to do with the 4x4 and it worked. Hope this helps you out

this is the same as mine was doing found air vac lines falling apart been good for over a year allways go to the simp[le things first

do you have spark?

I have a 1999 chevy blazer that stuck in 4 wheel drive. How do you get it out.