chevy 4x4 trouble

[honda98]

i have been trying to use my 4wheel drive. i have a 2000 zr2 blazer and every time i try to engage 4hi, or auto 4wd it wont engage. it has the electronic push button set up and if i select any of the 4 wheel drives it just blinks for like a minute then locks back into 2 wheel. i just bought the truck in september of this year.

guy from work said they have a centrifical clutch and they wont engage unless your moving but i couldnt get it whether i was moving, in park or neutral. anybody have this problem or have any ideas on how to fix it?

[TCracin440ex]

sounds to me like the actuator on the front diff is bad.

[CJM]

Try this:

Stop, put it in neutral and engage and roll a bit forward (at least a few hundred feet). If it still wont engage then yea you got issues.

The 4wd system (at least the older ones) is vacuum operated or possibly electrically operated the as TC says the actuator could not be working properly for a variety of reasons.

See if you can dig up a self test for it by googling, should be a way to check to see how it operates, what controls it and why it doesnt work (trust me google is your friend).

Im betting its not getting the signal for whatever reason. If its vacuum operated could be as simple as a hose unplugged or has a leak, electrical could be a fuse, short in the system or the switch itself.

[yellowzo3]

I KNEW it was going to be this exact problem when I saw the thread title.

This isn't too uncommon in Chevy's push-button system. Our neighbor had the same problem on his Blazer and I believe we did as well on our Tahoe.

Check this out:

http://www.blazerforum.com/forum/showthread.php?t=34965

If you want to search google there's tons of discussions on it so I'm sure you could diagnose it yourself like CJM said. But yeah, don't feel bad as this isn't uncommon.

[finsteratv]

its a chevy :p hah jk

[honda98]

thanks for the help everybody. tht blazer website seemed to have a preety good explanation. i googled it and i found another explanation too. seems preety common in chevys. ill check it out tommarow when i can actually see. ill tell you guys how it went. thanks

[brian76708]

most likely a vacuum leak or the canister under the battery


i suggest you join zr2usa.com

[TCracin440ex]

Originally posted by brian76708
most likely a vacuum leak or the canister under the battery


i suggest you join zr2usa.com

the newer trucks dont run off vacuum. the older ones do

[TheIceMan]

It's more than likely the encoder motor (electric actuator),usually about a $350 part.
Try this:with the blazer running,put in neutral,foot on brake,then press your 4wd switch(4-hi),while the light on the 4wd switch is blinking,shift into drive...it should engage. Taking it out of 4wd is the opposite. Hope that helps,the '97 I had did the same thing.

[TCracin440ex]

Originally posted by brian76708
uh no, if its push button the 4wd engages off of vacuum in these trucks.

no sirr, the older stuff was vaccum. the new stuff is all electronic. there is an electronic actuator on the front diff that locks the frontend in 4wd. and the actuator going out is a very common problem in these trucks as well as the half ton and up

EDIT: brian76708 why did you delete your post?

[brian76708]

Originally posted by TCracin440ex
no sirr, the older stuff was vaccum. the new stuff is all electronic. there is an electronic actuator on the front diff that locks the frontend in 4wd. and the actuator going out is a very common problem in these trucks as well as the half ton and up

EDIT: brian76708 why did you delete your post?

i deleted it because i didn't want to deal with your ****...

but what i do know is a vacuum leak can still cause havoc with the 4wd system on these trucks. I have had it happened when a hose came disconnected .

and it could be the encoder motor.

[TCracin440ex]

Originally posted by brian76708
i deleted it because i didn't want to deal with your ****...

but what i do know is a vacuum leak can still cause havoc with the 4wd system on these trucks. I have had it happened when a hose came disconnected .

and it could be the encoder motor.

you just hate being wrong thats it. the newer trucks do not run off vacuum. do some reseach. google it, idc. but the older stuff does run off vacume. my dad used to have a 90s model s15 gmc and in order to put his truck in 4x4 he had to unhook a vacume line off the motor and hook it to the canister and then shift it into 4x4.

[TCracin440ex]

brian. i hate to say this but looks like you was right. im man enough to say im sorry. looks like the s10/blazer still runs off old technoligy. i just done some more research. but the t-case still has an electronic motor that controls the engaging and disengaging of the 4x4. the actual front dif does have vacuum on it to engage the front diff.


to the op: here is a good link and you might find some helpful info
http://townhall-talk.edmunds.com/direct/view/.f1a7768/7


brian once again i appoligize.

[witech]

http://www.kylestubbins.com/node/11
First off i would suggest doing a little internet search and youtube for the wealth of information out there.
I would not recommend throwing parts at it as it seems most of the chevy 4wd problems can be remedied with cleaning up terminals and actuators.

[honda98]

ok boys and girls i checked the fuse and it wasnt that then i tried that put it in neutral then press the button then shift to drive and that didnt work. just read the article witech put on and talks about replacing an electrical module on the passenger side im gunna try that. thanks for the responses everybody ill give you all an update after i try that

[brian76708]

http://www.zr2usa.com/mboard/index.php?showtopic=21989