First off great forum you have here

I recently bought a 1995 blazer. I'm not too familiar with these vehicles, which is why I came here lol. My problem is with the 4x4, it is pushbutton on the dash.

When I try to engage it, I can hear it make some sort of noise outfront down below, which I assume is the differential. The light on the switch stays lit, however the front wheels don't pull.

I have checked the fuse, took the switch apart and cleaned all connections, took the box behind the passenger kickpanel and cleaned all plugs and connections there, checked the actuator under the battery tray today for rips or tears, all looked good.

I'm assuming its a vacuum line issue. I think the engine is not original, and the guy I bought it from said he replaced the tranny so I really don't know where the vacuum lines originate from and where they should go to tell if they are correctly ran and hooked up.

I'm going to break down and take it to the garage, which I really don't want to do (lot of shady garages around here,unfortunately sometimes you have to) if I don't get any more ideas. I'm fairly sure it's vacuum related, just don't know I guess.

 

Did you watch the actuator to see if it is pulling the cable when the 4wd is engaged?

Here's a thread with great info https://blazerforum.com/forum/tech-a...ill-help-7180/

Here is a good article also GMC Sonoma & Chevy S-10 Transfer Case Vacuum Switch

 

Thanks for the links.

Where does the supply come off the motor at? Also, I didn't see that 3 prong vacuum fitting that goes on the transfer case when I was under there, where is that located on it? Thanks again for the info.

Also, to watch the actuator, do I just start the truck, then remove the battery and have someone engage it? Sorry for all the questions, it's the only way I'm going to learn I guess lol thanks

 

The supply off the motor is located at the lower intake manifold, driver's side, rear of the engine. You will see the vac line coming out of it. The 3 prong transfer switch is on top of the transfer case and has 3 vac lines going into it. To watch the actuator, I would take the batt out and the tray, then useful jump cables to connect the battery to the battery cables. Insuring there is not any metal to metal contact on the body or anything. Another person start the truck and i would watch the actuator. Then I would have my helper switch the transfer in and out of 4wd while I watch the actuator.

Report back your progress so others can follow until you have fixed. Plus there are more knowlegeble guys on here than I who might weigh in.

 

I'm at work, but I will try this when I get home. You may be right but you have been most helpful. I'll report back.

 

Ok, a little update. I haven't had time after work to trace all the vacuum lines etc. However, I did have a helper push the buttons on the dash while I watched the actuator under the battery tray...no movement at all. So I pulled on the cable and put a pair of vice grips on it...I have 4wheel drive lol. So it's obviously a vacuum problem. However I got to thinking, why couldn't I take the cable out of the bracket it is in, and route it into the cab...think along the lines of the old manual chokes?? Then just pull it a bit to engage the differential?

 

Ok, another little quick update. Went to go to work this morning. Got about a mile down the road and fealt a bump...lost 4 wheel. So the vice grip idea didn't pan out. I'm going to try the cable to the cab idea if I could get some feedback on whether it might work or not. How far should the actuator pull the cable out? It only moved out about an inch or so...

 

It will work...others have done it:

https://blazerforum.com/forum/tech-a...-system-31138/

Sounds like you're getting the right amount of movement of the cable. It does not have to move too much to do what it's supposed to be doing.

 

Wow, thanks a bunch. I did a search today for something like that but must not have had the right combo in the search...thanks you guys for the help,I think I'm gonna like it here lol

 

Just thought I would make a little update on my success's. I finally got around to doing the manual cable on the truck. It was actually easier then I figured it would be. Anyhow, it works!! Only thing is I got the exact same cable in the thread, and I can't quite figure out where the locking position is. I know it's not rocket science lol but the handle appears to screw in and out and it doesn't look to actually have a locking position per say. Anyways thought I would post that the manual locking cable mod is a viable option for someone wanting their 4X4 to work and like me, had a vacuum leak issue.