My blazer wont go into 4wd lo or hi. I checked the actuator under the battery tray and it's working and I can hear the case switch when I put it in lo but not hi. when it's supposed to be in lo I don't think im actually in 4wd, the case is definetly in that I can feel but it seems like the front end isn't. And I can't find any indication 4hi is working at all. I just ordered a new switch for the dash as it's been acting up awhile now.


Just looking for some input on where to look if that doesn't take care of it. I have the 4 button switch if that makes a difference and I can hear the box under the passenger kick panel clicking when I switch.

 

Push the hi or low button, get underneath and try turning the front driveshaft, if it doesnt turn your transfer case is doing what its supposed to do. if engeaged it could your vacuum or possibly a stuck actuator cable, if your actuator is good also

 

Check what newguy said, and if the front drive shaft is locked but the front wheels are not engaged then it's something associated with the front diff. Most likely is that the front actuator is not receiving vacuum or is damaged. If you have a 3 button 4wd switch it could also be the vacuum switch on the top of the transfer case not engaging the actuator under the battery tray.

 

OK. I ran it through 2hi and 4 hi and I couldn't turn the driveshat in either. I double checked the actuator to make shure its working and it is. I can hear the encoder working but 4 hi sounds like a real short movment compared to 4lol. I got my new switch and that is now working correctly. BUT the front wheels still wont turn. Could the actuator cable be broken? Its not like I rarely use 4wd, I use it a fair amount. I had my kid give it some gas and spin the tires while I watched the front driveshaft "Not from under the truck either, I was back from the side and all I could see was the front u joint" It did spin. I did replace the front drive axles recently, don't know of anything I could have screwed up that would affect this but?
I have a 4 button sytem with 2hi, 4hi, 4lo, and auto 4wd.













Any ideas? Really need to get this fixed, Weather is getting white up here and I have a 75 minute drive to work.

 

next thing i would try is the actuator switch Dorman - Help Transfer Case Switch 49315: Get the best Transmission Transfer Case Motor at Advance Auto Parts.. Did you yake the battery and the tray out and look at the vacuum actuator underneath? One rip and its no good. While there you can check the cable

 

I removed the tray and reconnected the battery and held it at an angle so I could watch the actuator while my son ran through the buttons for me. This way I could watch the actual movement. All looked good. Could it still be the switch?

 

Well that would mean the transfer case switch is working. So its the cable or where it connects on the differential

 

I kinda thought that, wasn't really what I wanted to hear but, is what it is. I'm more experienced with the motor and rear end than the tranny and front end. Guess i'll get to learn a few things.


Thank you.

 

Good luck, let us know what you find