96 Blazer 4wd help!

[TR Custom Parts]

Well, we got our first snowfall today in CT. No big deal IF you have 4wd. Got into my 96 S-10 Blazer and pushed the 4WD button and it lit up and clicked like it always did. Nail it out on the street and the truck goes sideways. Figured it was just icy under the snow but apparently the 4WD is not kicking in. Anyone know where to start looking for the problem? Tried going into 4WD about a month ago just to make sure everything was working OK and I could feel it kick in. Of course now that I need it, it doesn't work.

[Reaper]

not sure about the s-10s but on the full size trucks its an electronic locking device thats in the middle of the indp. axle, you will see it. its about the same size a single serving V8 can with 3 wires coming out of it toward the pass. side of the truck. they are easy to replace and kinda cheap. if i was you i would go to JC whitney and get the manual actuator.

expect to pay 100 to 170 for the part and about 30min to replace it.


Dathan

[Duff73]

I have a 95 blazer 1 touch 4wd. I have replaced the contactor for the 4wd about 4 times now. It's a $75 dollar piece. There's a contactor in there and if you pound the switch to engage when it's trying to engage you'll burn it out. I've found that even tho it's "on the fly" 4wd it's generally not a good idea to do that that. I usually wait till im stopped to engage 4wH. Hope that helps.

If it's not the switch you could have a bad board which runs about $150-175 depending where you get that from. I've replaced that too btw

There's a good website similar to ours for s-10 and blazers go here.

http://www.s10forum.com/forum/

[Loosenut]

There is a cable that goes to the transfer case or trans that gets bent or damaged and won't operate. It happened to my 97 a couple years back. It is a very common problem, it was on back order.

HTH
Andy

[NJTurbo]

A few things....

1st: Pull up your battery tray (3 13mm bolts) and look at the vac servo under there. Is it torn? (If so replace it) If you squeeze it (carefully) is it pulling on the cable? (it should if the clip is seated properly). Is the vac hose attached?

2nd Follow the vac hose from that diagram to the vac switch on the transfer case. Check for cracks, breaks, et-al. (If you've had the abs recall done it will go from the diagram to a t connected to the modulator attached to the water bottle then down to the transfer case)

3rd follow the other vac line from the switch to the main vac system. Again no cracks or breaks should be present.

Now if all this is good, Chances are it is the switch on the vacuum case.

If this doesn't solve it it's your encoder motor. Good luck keep us posted.

[TR Custom Parts]

Thanks for the tips. Will have to wait for it to get a bit warmer before I dive into this. Wonder if the cold temps we are having in the Northeast have anything to do with it. Don't see why but it was working perfectly within the past month when I was testing it. The Blazer has 135,000 on it so I guess I can't complain.

[NJTurbo]

The cold front is suppose to break Wednesday in the high 40's. I left the house this morning 6 degrees. I hate winter anymore.

If you cannot figure it out, PM me we own the Danbury Chevrolet in Conn. I am good friends with a few techs there. I can get you in there without getting rapped

[TR Custom Parts]

Messed around with it a bit today.

Vacuum actuator under the battery case was fine, had my son working the buttons while I watched and I could see it pulling the cable and holding.

I can hear the encoder motor working back on the transfer case but don't know if it is doing what it is supposed to do but it IS making noise.

When the 4wdHI button is lit up I can spin the driver's side tire and the other tire spins the opposite way. In 2wd the tires both free wheel.

Wonder if I blew the transfer case??

[NJTurbo]

Mark double check all the vacuum lines make sure there is no cracks. Also it sounds like the encoder is not working like it should. I doubt you blew the transfer case IMO,.

[TR Custom Parts]

Well, just went out to snow blow the driveway and had to move the Blazer. Now the freaking 4wd is working! Put it into D instead of overdrive and it was fine, don't think that should make any difference. I don't like when things fix themselves.

BTW, it IS working in OD too now. Took a blast down the street in the snow and it was fine. When I turned around in a semi dry area you could feel that it was in 4wd by it bucking in the front, sort of like how a Locker rear feels.

Would think it would be an electrical problem if it "fixed" itself like this.

[NJTurbo]

It sounds like the encoder may not be enabling the differential at times. Cool it works, Murphy's law we will get blasted with 3 feet and it will not work

[TR Custom Parts]

Just got back from a longer drive and it is working fine. Murphy's law always seems to find me. Will see next snowstorm.