Ok guys. I need some help. I have another thread going https://blazerforum.com/forum/2nd-ge...no-4-lo-91034/ about my 4x4 not working. Before pulling a lot of stuff to diagnose, I wanted to check the TC switch to see if I had inserted the tower cap that had the 3 vacuum hoses correctly. When I took the cap off, I noticed that the plastic towers on top of the switch rotated freely. Is this normal? I took it out and put a vacuum gauge on it and no amount of vacuum would retract the ball. Again, is this normal?? With the spring pressure on this ball, I don't think engine vacuum would be strong enough to pull it since I have a hard time to push the ball in with my thumb. It's a Dorman 600-500 made in China. I thought Dorman products were made in the US!!
Don

 

vacuum doesn't pull it the shift linkage inside the Xfer case pushes the ball up and every one that i played with the top was solid - even so the switch has a stub sticking up to align the hose assembly - if you look on the assembly you can see the notch in the rubber
With the three lines on the switch one of them is vacuum, vacuum to front diff actuator and last goes to a vent usually T'ed into the Xfer case vent to release vacuum on the actuator when switched to 2WD

 

So the top was solid. Thanks' a bunch.
Don

 

I had a problem with this a couple years ago. My defrost quit working. We replaced the transfer case switch with a new one from Napa. It didn't fix the problem. I bought the second one that Napa offered, and boom there you go now it works fine. Weird, I think the 2nd one was from Dorman.