96 Chevy Blazer -4x4 not engaging

Ok so im trying to diagnose whats causing my 4x4 not to engage and I'm stuck.

The last thing I've tried is hooking vice grips up to the vacuum actuator chain because it's not getting any vacuum. The chain is extended as far as it can go (probably about an inch) and hooked the grips up to it to lock the axle in place. I go for a ride in the snow and I'm still only getting power to the rear wheels in both 4hi and 4lo.

Anyone have any idea where I should go from here? Could the chain be the problem or could it be something more complicated on the axle? Please any advice is appreciated... its snowing outside and it's killing me not driving.

What transfer case?
What is not engauging?
Front axel or transfer case or both.
Find out where you are not getting vacuum.
Check fuse and wiring and plugins and Pull codes.
Post back codes.
If 233 or 243 gground pin 13 on diagnostic connector and read codes from shift button lights.

http://www.automotiveforums.com/vbulletin/showthread.php?t=572914

What transfer case? I just got the truck so I believe it's whatever came with the truck. It's the 3 button electronic push button 4x4, not the manual unit on the floor.

What is not engauging? The front axle's not engaging when im manually pulling the vacuum actuator cable and attaching vice grips to hold in place (manipulating the vacuum system). The cable moves, but the front axle isnt engaging.

Front axel or transfer case or both. Transfer case is fine when i tested the driveshaft. The front axle does not engage when pulling and holding the actuator cable.

Find out where you are not getting vacuum. Is the vacuum the issue if I'm manually pulling the cable myself and nothing engages?

Check fuse and wiring and plugins and Pull codes.
Post back codes. whats the easiest way to check codes? Will i have to bring it in to a shop? will a mechanical issue liek the one im having throw a code?

As in first post.
Ground pin 13 on diagnostic connector to get codes.
Front axel not engauging.
http://www.automotiveforums.com/vbulletin/showthread.php?t=572914

Thanks MT.. I really appreciate your help and guidance.

Might be a dumb question but im new to the blazer world so im doing my best. Any guidance where i can find thre Ground pin 13 on diagnostic connector and what ill need to pull codes?

http://www.troublecodes.net/OBD2/

Ground pin 13 and turn key on and read codes on shift button lights.
Post back codes.

pardon my stupidity but i tried searching around and didn't find much in terms of instructions. How do I ground that specific pin? Will I need certain equipment or is this something I can do in my driveway?

See which pin is ground on that diagram and use a paperclip to jump from pin 13 to the ground pin.

chassis ground or signal ground? I see pin 4 for the chassis ground and pin 5 for the signal ground?

So all i need to do is get a paper clip, make a connection from pin 4 or 5 to pin 13 and turn the car on and codes will come up on the dash?

chassis ground or signal ground? I see pin 4 for the chassis ground and pin 5 for the signal ground?

So all i need to do is get a paper clip, make a connection from pin 4 or 5 to pin 13 and turn the car on and codes will come up on the dash?

Chasic ground or frame ground or battey neg.
Ground pin 13 turn key on and count flashes on shift buttons lights.
Easy as falling off a log.

Post back any codes and check for where it is losing vacuum.
Good Luck

I got a paper clip and bridged pin #13 to pin #5 (signal ground) and didn't see anything i don't normally see on the dash when starting the car up. Am I doing this right? Am I missing anything here?.. i must not be doing something right...?

Go for pin 4 chassis ground for and 13.
You should see shift buttons light up and go out or flash code.
GOOD LUCK

It's about 10 degrees outside here in CT so ill check it out tomorrow and post what I find. Thanks MT for your help with this... I really appreciate it. Hopefully Ill somehow get this 4x4 going before the winters over.

Im putting the keys in with it bridged from pin 4 to 13 and no lights are flashing that normally dont flash. I turn the car on and only get a normal light below the P (park).

The only thing i can think of is my check engine light on the dash doesnt work.. would that have an effect on this?

Im putting the keys in with it bridged from pin 4 to 13 and no lights are flashing that normally dont flash. I turn the car on and only get a normal light below the P (park).

The only thing i can think of is my check engine light on the dash doesnt work.. would that have an effect on this?only 27 drg in VA the lights you need to watch are the 4wheel drive control indicator lights at 4wheel drive selector panel on dash good luck

Do not start the car, just turn the key to the run position.

ok so i bridged pin 4 to pin 13 and turned the car on and im getting all 3 lights (4h, 4l, and 2h) blinking at the same time about 4 seconds apart and not stopping. Not really sure how to read that in terms of codes but any idea what that means?

You need to count the blinks to read codes.
Include long and shorts and how many long and shorts.

I get the same 3 lights blinking about 4-5 seconds apart and just doesnt stop. I counted up to 40 and just gave up because i figured i must be doing something wrong because it would have just kept going. How high should I be counting up to?

I get the same 3 lights blinking about 4-5 seconds apart and just doesnt stop. I counted up to 40 and just gave up because i figured i must be doing something wrong because it would have just kept going. How high should I be counting up to?

If no codes the light should come on for buld check and go off and not flash.
If a code or codes,
The light will flash code and then after a 3 second delay reflash code agiain.

What are the first set of flashes or flash.
Codes are from 1 to 4 or 1 to 4 flashes right together.
Watch that light real close and count flashes and then after 3 second delay count them again and again and again.
Up to 4 times.
Post back

Ok now its not throwing any codes. I put the key in the on position, all three lights flash for about a second and turn off. I tried disconnecting and trying again and it did the same thing. Is it possible to not throw any codes and still not be working because it's definitely not working..

Ok now its not throwing any codes. I put the key in the on position, all three lights flash for about a second and turn off. I tried disconnecting and trying again and it did the same thing. Is it possible to not throw any codes and still not be working because it's definitely not working..

How many flashes?
Does it repeat the flashes or just turn off?
Unhook battery to clear codes hook battery back up and recheck it.

This is what happens... I put the key in the ignition, turn key to on position, 2h, 4h, and 4l light up solid once for about one second and then nothing else flashes. I have a lunch break in about an hour and ill try again then after i unhook the battery.

This is what happens... I put the key in the ignition, turn key to on position, 2h, 4h, and 4l light up solid once for about one second and then nothing else flashes. I have a lunch break in about an hour and ill try again then after i unhook the battery.

What happened to all of the flashes?

If no codes you will have no flashes.
Better check out the vacumn supply.
Get a all at a online sub or aa factoty repair manual for some good help and repair info on it.
http://www.alldata.com/products/diy/index.html
Good luck.

ok just unplugged the battery and plugged back in and its doing the same exact thing as it was doing before. Bridged from pin 5 to pin 13, i turn the key in the ignition to the on position (without actually turning on the car) and all three lights turn orange for about one second. They turn off for 5 seconds then all three flash again, they turn off for 5 seconds then back on, and so on and so on. There are no quick flashes, just the repeating of all lit up then off for 5 seconds, then back on. Any idea?

Sounds like no codes.
Get a good repair manual and work on the vacumn end of it.
Good luck

Or it could be a code 1 repeating itself.

Code should flash 3 seconds after key is on.
If it flashes one time it could be code on.
Try it using a frane or chassie ground instead of pin 5 use pin 4 as a ground.

Do you think the vacuum part even matters at this point? Back to my original question where im pulling the actuator cable (like the vacuum system would do) and it's not locking my front axle in gear/4x4 mode.

I pull the actuator cable as far out as it goes, i hear a click, attach vice grips to keep it pulled back, and drive the car but its still only in rear wheel drive....?

Do you think the vacuum part even matters at this point? Back to my original question where im pulling the actuator cable (like the vacuum system would do) and it's not locking my front axle in gear/4x4 mode.

I pull the actuator cable as far out as it goes, i hear a click, attach vice grips to keep it pulled back, and drive the car but its still only in rear wheel drive....?


Get some good repair info and go threw the repair flow chart for code 1.

On the front actuator or vacuum.
If you pull cable far enough it should lock in front axle.

http://www.automotiveforums.com/vbulletin/showthread.php?t=572914

Now when you say "Code should flash 3 seconds after key is on" it actually does do something different sometimes when I start it and it kind of sounds like that. I've tried this so many times, sometimes it will do something slightly different. I'll put the key in the ignition, turn to one, all three lights turn orange immediately, 2 or 3 seconds passes, then they all light up again. After that one shorter delay, it’s a 5 second delay in between each flash and just keeps going. Could that possibly be code 1? What is code 1?

Also "On the front actuator or vacuum. If you pull cable far enough it should lock in front axle." Thats my problem, it doesnt lock no matter how far i pull it. i manually pull the cable out thats connected to the actuator (under the battery) but it never locks the front axle.

Code one is a transfer case module internal fault.
FIRST CHECK IS FOR GOOD 12 VOLT POWER TO IT on circuit 1640 the orange fuse wire for good 12 volts.
If good voltage it is replace the transfer case module.
Best to get good the repair manual or the all data online sub and go threw the repair flow charts.
Good luck

If the transfer case was the problem, would the drive shaft still lock when in 4x4 mode? It locks when in 4h, but if i put in 2h, it moves freely?

The code one is for transfer case module not transfer case.
If transfer case locks into 4W and locks front axel then the axuator has to pull the cabel to lock in front axel.
It has to have engine vacuum to front axel threw the transfer case vacuum switch to solenoid and solenoid has to have signal to apply vacuum to actuator to lock in actuator.
Check the front actuator part out for vacuum and signal to lock up.

http://www.automotiveforums.com/vbulletin/showthread.php?t=572914

So a bad transfer case switch could possibly be the culprit?

So a bad transfer case switch could possibly be the culprit?
Check it out.
http://www.alldata.com/products/diy/index.html
Could be Along with several other things.
Proper testing is in order.

And also remember the code 1 which is not good.
Good Luck

Hey MT quick question for you... with those whole code 1... does this have anything to do with the vacuum system? I was hoping a new vacuum switch would be my answer but it wasnt and im still not getting any vacuum.

What im thinking about doing is forgetting the entire vacuum system and going with the posi lock system. The only problem is my front axle isnt engaging even when manually pulled.

My questions is...If i got the posi lock, would code 1 still be an issue?

Code 1 is for control module.
But if control module is bad it may not switch the vacuum to front actuator.
Untill you fix the code 1 it you will have a code 1.
Get you some good repair info to fix the 4W.
http://www.alldata.com/products/diy/index.html

Anti-slip rear end is not going to fix the 4W
Good Luck

yeah it sounds like this control module is really might be my issue. Before I go an buy a package at that link you gave me, any idea if a control module a big/expensive job?

yeah it sounds like this control module is really might be my issue. Before I go an buy a package at that link you gave me, any idea if a control module a big/expensive job?

The link I posted gives you all of that info.
The 26.95$ for the sub can save you up into the 100-500$ or more in repairs.
I have expained all told you all I can.

Time for you to.
Get yourself some good repair info.
Good Luck