Hello everyone, i hope one of u can take the time to help me out on this.

I got a blazer s10, 94, with automatic trans, and electrical 4wd switch.
the problem is, i cant get it into 4wheel drive.
when the problems started, i was out driving, i pressed the 4high button, it would blink for awhile, then stop. also tried 4 low, same problem. i can hear the click from the TCCM, but nothing else happens. have tried again and again to get it engaged, but it have just gotten worse now. (a month later)
Now, when i click either one of the buttons, both will light up, once in a while they blink, most often it is just a constant light on both buttons, or no light at all, but still i hear the tccm click. Also, it wont even respond if im not in park, or neutral. only then, i will hear the tccm click, and maybe see some lights on the buttons, sometimes not.
i dont hear any other sound when i try activate the 4wd than the tccm click, no clunks or nothing, just the tccm click.

I have read and read on this, and other forums, and tried alot of the stuff i read, but no luck so far. things i tried:

-Check the tccm fuse, pulled it out for an hour, then turn the key until 4wd lights came on, then off, then on and so on, 5-10 times.

-checked the electrical wire pluggs in the tccm box, and the box in the middle,(ecm?) both seems to be clean.
-checked vacuum hoses to the vacuum actuator, and the vacuum actuator, both seems fine.

any ideas what the problem might be?
by the way, i read somewhere about a ALDL cable or something located in the car, where u can check for errors with, if u put a wire between A and J, it will blink codes at the 4wd button. does it work with my car and model?
if it does, were do i find this cable or box or whatever it is? i have looked everywhere, no luck finding it yet.

found the thread again:
http://forums.s-series.org/viewtopic.php?t=50947
it says under the drivers side dash, but where? and what does it look like?
i got the 4wd push button over my light switch by the way. (to the left of the steering wheel)

sorry if I explain bad or bad english, not my main language im from Norway.
If any of u got some advice, or ideas what it might be, please answer, i appreciate all the help you can give me.

If you want more info just ask.

 

The ALDL plug is under the driver side dash and looks exactly like the image posted in that thread. It should be located along the lower edge of the trim panel under the steering wheel.

Check out this thread for some trouble shooting ideas concerning the encoder motor:
NV233 transfer case / encoding motor switch

The code descriptions are the same as for the 2nd gens and can be read about here:
OBD2 Non-Automatic Transfer Case Diagnostics

 

i just took a look under the car, and i found some wires, going to the tranfer case shift motor, looks like they have been damaged by heat, and a black wire (probably ground) is cut in two. (looks like the outter tube around the cables have melted and some of the cables have been damaged.

i think this is how my problems started!

 

That is a very good possibility. Repair those and let us know if we can be of further assistance.

 

thank you for your help, and quick reply.
i will look into this when i got time, gotta go right now.
I will update u all if this solves my problem or not.

 

found the ALDL plug right away after reading your instructions, and i tested this method, i came up with code 2, and code 3.


code 2 - Encoder fault: Every time the t-case position moves, the TCCM checks the encoder’s readings during the shift. If something isn't right, it will increment an error counter by 4. A successful reading decreases the counter by 1. If the counter reaches 32, the TCCM determines the encoder faulty, and bypasses 4hi. Check for loose wires and excessive dirt/moisture near all connectors.

code 3 – TCCM (Transfer Case Control Module) motor circuit: Basically, every time the TCCM is powered up, it tests the encoder motor. If something isn't right, it will trip the code 3.

so the codes are also pointing me in this direction, the damaged wires.
now im waiting for better weather before i fix my problem, its -14celcius outside right now.

 

its the trasnfer case shift motor another term encoder motor. its holding on by 3 bolts on the side of the trasfercase. might have to drop the front drive shaft to get it out. and take some pliers or knife and cut some of the plastic off of the motor cause it will make life sooo much easier getting it past the yolk unless you get a yolk puller and pull it off. when you get the bolts out you will have to pull it away from the trasfter case past a little 3/4 in nub then wiggle it out. but cutting some of the unnesusarry plastic off will help alot. thats if fixing the wires dont help.

 

okey so now i have fixed the damaged wires, still cant get it into 4wd, not 4hi, or 4low.
good news is the 4wd switch lights work as they should now, atleast for a few tries. i try click 4hi, it blinks and blinks, until it eventually turns off again. still only sound i can hear is the tccm box, but i hear it 2 times now. a click when i press the switch, and a click after awhile, when the lighting stops.
after a few attempts, the lights will not blink anymore.
also, i dont got code 2 anymore, now i got code 1, and code 3.
so the wiring and connections should be ok now i guess?
if i pull out the tccm fuse, and the ecm fuse, (above the tccm fuse) put them back on, and try the ALDL cable trick, without trying to get it into 4wd before i test, i only get code 1. if i try a few more attempts to get it into 4wd, and then try the ALDL trick, i get error code3 again.
Also, sometimes i dont get code 1 either, its there most of the time but a few times i tried, it was only code 3. so i got a weird problem..

is it possible the damaged wires caused the problem to spread, damaging other components, like the encoder motor or tccm? by the way, i had no blown fuses.

so what do you guys think my problem is now? im hoping its a small problem, thats why i ask again, before i replace the encoder motor or other stuff. thanks for all your help.

im going to read up more on how to find out about my problem, and be out at the car trying to fix this so I just thought i should write here if any of u got a quick answer, since the problem has changed alittle.

its pointing towards the encoder motor, but can it be something else? in that case, what?
again thank you all for your help and advice.

update: the vacuum actuator is activated the second i start my car. shouldnt it be turned on, only when im trying to engage 4wd, and when it is engaged? im in 2wd now and the second i started, it had vacuum.

this is probably not related to my current problem, still just wanted to add it to the thread.

edit: now i have also taken off again, and cleaned all wires from the encoder motor, and the tccm, taken off the battery and fuses for an hour, cause some said it fixed their problems, well my problem is still there. only get code 3 now when i check..
starting to believe i have to get a new encoder motor.. can it be anything else? think hard you guys who know these vehicles inside out, cause this will costs me alot of bucks..

 

Did you make sure to get the wires correct when you repaired the damage?

Have you run down through the diagnostic chart in the 2nd link I posted above for code 3? That will tell you if you have a wiring problem or an encoder motor problem.

And no, you should not have vacuum to the front axle engagement actuator when in 2HI. Only when in 4HI or 4LO.

 

yeah im sure I did the wires correct, they all got different colors so it wasnt hard..

I did read up on all info I got, but I didnt understand it all.. I read it all again and I understand it alittle better now, still not all of it thou.. electricity is a thing im not so good at..

Im gonna figure this testing thing all out, then im gonna give it a try.. I let you know what I find out wen im done.