4X4 problem! *solved (vac line)

[dansby660]

My 2003 S10 crew cab 4wd is not working. The push button lights change. I can hear a click like it is engaging but only the rear wheel will spin when trying to use it. I just got it out of chevy dealership's shop. They put in a new radiator, new cruise control module, fixed a axle seal, oxygen sensor and a differential seal. I don't think any of that should have affected the 4wd though. It just ran out of my extended warranty and they were supposed to fix any problems. Can anybody give me any ideas of what to check out to see where my problem is? Thanks, Dale

[HenryJ]

Check the actuator under the battery tray and see if it is working. in doing so the battery cables will be disconnected and reset the transfercase module. That has worked for some.
Check the vacuum lines to make sure they are not dry rotted , leaking and properly attached to the reservoir.
Checking to make sure the front driveshaft engages in 4x4 will tell you if it is really being shifted.

Take your time and do some looking around. Many before you have gone through exactly the same thing. Lots of reading to do to solve a not so easy to find problem.

[dansby660]

Thanks. I will do some searching. I also just changed the battery. Not sure if that would have done anything to the transfercase module but I will sure check it.

[HenryJ]

Disconnecting the battery cables for a few minutes should serve to reset the TC module. That has helped some.

[dansby660]

Still have 4wd problems but found a vacuum hose that wasnt hooked to anything and was sucking air. Can anybody tell me where it might go? Thanks

[HenryJ]

The pictures are tiny and I can make out no detail. I will take a guess and say that it is to the vacuum reservoir in the left front fender. Feel under the lip for the nipple it is very hard to see.

That will be the reason that the front axle will not engage and the HVAC not work properly.

[dansby660]

Thanks a lot henry. You can mark this as another problem solved. It was very hard to find where that hose was suposed to hook up but I caught a glance of something black inside the fender and felt around to find a nipple sticking thru the fender. I plugged it in and tried the 4wd. The first time it just blinked in hi and low when I tried them and didnt do anything at all. I went back to park, then neutral and tried it again and the lights locked in. Then I went to test it out and it worked like a charm. It pulled right up the ditch I got stuck on yesterday. Thanks again and heres to hoping I don't have any other problems anytime soon.

[HenryJ]

Glad to hear it was a simple fix!