Ok so my 4wd has not been working for quite some time, I don't really need it but was curious as to what you all think it could be. When I push either 4Hi or 4Lo most of the time it acts as if it doesn't have power, but I know it does because when I turn the key just before starting my blazer it lights up with all the rest of the idiot lights. The other times it just blinks both Hi and Lo lights and does nothing. Today it blinked 5 times if that helps at all.

I was thinking it could be the Transfer Case Control Module because I can hear a "click" coming from the diagram on the passenger side kick panel, but I noticed the other day that I have no cruise control either "for what ever reason" and I had read that the cruise control and 4x4 system use the same vac system is this true and if so what could be the culprit of making these things not work? And where should I check 1st to be able to hit the trails again?

I have a 94 s10 blazer w code and have changed the switch a few times.

 

Sounds like a definate vacuum problem to me. I would start at the rear of the engine - right side. I think this is where the vacuum is tapped from. There should be a vacuum line coming off the intake manifold and splitting off to other directions. You can pull the line off the cruise control servo (just forward of brake master cylinder) on inner fender to see if you have vacuum there. There should be two lines connected to the servo. The front drive actuator is located below the battery tray if you want to check for vacuum there. The black ball looking thing is actually a reserve vacuum tank mainly for the cruise control and should have a line running to it too. I guess you're familiar with the t-case switch. Just make sure everything is hooked up and hooked up properly. It ain't rocket science. There are some check valves in the system. If you don't see them, post again and I'll look them up for you. I have a factory manual on this vehicle.

 

does it make a clicking noise when trying to go in 4hi? there is a vacuum line connector on top of the transfer case (under drivers seat under truck) that has a tendensy to have the lines crack. and if not bad there. try to follow the vacuum lines and see if they are cracked anywhere else.

i have a body lift so it was easier for me but mine were cracked. 3 of the 4 (i beleive) lines run to other points on the transfer case, and one should run to the 4wd actuator under the battery tray. but if it clicks its not a vacuum problem most likely. thats ussually a mechanical problem. My shift fork in my front diff was snapped in half. Which i was told was also a common problem when often using 4wd.

I dont know if any of this rant actually helped but i tried lol. Good luck

 

ok, well when the switch has power, when I push either 4hi or 4lo I hear a "click" that sounds to be coming from the passengers side of the dash. I know that is where one of the diaframs are, but a lot of the time once I start my truck, both the green and orange light blink then the switch has no more power

 

Awesome I got my 4wd working thanks guys, but only 4Lo will work no matter what I do 4hi won't work. I figured out that the switch ONLY has power when its in neutral and even then it has to be in a certain spot, so I'm guessing there is some sort of neutral safety switch? I got another switch I can swap in so I'm gonna try and see if that helps at all if not what would make the 4lo work and not the 4hi?

 

bump for more help?