4 Wheel Drive/SUVs: 1984 s-15 pu, vacuum diagrams, vacuum lines

Question
will not lock in to 4 wheel drive has a vaccum problem any ideas on what it could be or how to ck it

Answer
Mark,

Start out by tracing all the vacuum lines that run from the transfer case to the switches and relays.  Also check the vacuum motor on the front differential if there is one.  The vacuum switch on the transfer case is another component that could be bad.

If you wish to trouble shoot the problem yourself, then you should purchase a repair manual at your local auto parts store.  These cost around $20, and are for specific vehicles.  They are great if you plan on doing any of your own repair or maintenance as they have everything from troubleshooting techniques to wiring, and vacuum diagrams.

Carl