After doing some searching for a while I came to the conclusion that my transfer case was at fault. I ordered a new one and finally got a chance to put it on. I put it on and it never really got tight, the threads must be stripped, or is it supposed to be like that? I was on my way back to the house today and I gave the 4x4 a little test, put it in 4H the light just blinks it blinks and blinks never goes solid, never returns to 2H. Then I put it in 4L and I can feel it engage, and I had 4L. Could the switch not going in tight be the issue? I checked the TCCM and all the pins/plugs look to be fine. I also heard a whining sounds while in 4L. I couldn't really tell if it was in 4H or not, I did not feel a difference in the steering between 2H and 4L. What could the problem be? Snow is coming and the people that plow the streets in the neighbor plow only at the end of the year. By the why I have the auto 4x4, auto tranny.

 

What did you replace? Do you have the Auto4wd option?

 

T-Case Switch on front axle, And yes I have auto 4wd

 

you've got a rare truck if you have a transfer case switch on the front axle. Could it be that you've tried to install a t/case switch in the front axle-not sure that's possible-never tried it but....you may have put it -how did you hook it up?????vacuum-electrical plug?JP

 

I think we are having a problem with communication here... Do you have a part number for what it is that you replaced? Picture showing the location of the component?

If he is talking about the electrical switch, there should be nothing rare about it. There is an electrical switch in the front axle which indicates that the front axle has engaged. It is a simple switch which closes when the transfer case is engaged. It is located on the side of the housing where the engagement cable attaches to the passenger side of the front differential case (indicated by #11 on the image below).

 

Part number no...but yea #11 is what I replaced. I can hear the TCCM or whatever clicks when I put it in 4H or 4L, I can also hear the encoder motor engage too but in 4H it feels no different then in 2H (steering wise). When I put it in 4L the truck will jump and and I can't go over 15 mph (which I think is normal).

Sorry my post is all messed up. I hope this will help.

 

I realize where the switches are and how they hook up but...in the previous post he stated a 't-case switch on front axle.' That's what I found rare as I have never seen that in working on thousands of Blazers.jp

 

I checked the vac lines in the engine bay and they all look good. Where is the ground for the TCCM? Is it with all of the other grounds under the passenger carpet? And is there a vac line that goes directly to the T-Case? I know the acuator works and holds vac, sense it does engage the 4wd. How would I know if the TCCM has any codes on it? This is just making me nervous because the snow is coming and I don't want to be SOL when I need the 4x4.

 

try this-unhook the neg. batt. cable then the positive. Take one of the battery bolts out of the cable. Then..hold both cables together for thirty or more seconds. With the battery bolt out of one or the other cable, you can make a for sure connection. The last two bBlazers I had in the shop started to work using this procedure. If it works-it may work for a day, week, decade but if it works and then fails down the road-I'd be suspicious of the encoder motor. Do you have the 'auto' function? If not, you could also cut the vacuum hose that goes down to the servo(under the battery box) and apply vacuum to it-hopefully pulling the front diff. in thus the slip shaft would be engaged-indication all good from this point forward. Eliminating the servo, fr. diff. cable or any issue in the front differential. Laugh but try the batt. cable trick and let me know! JP

 

I just took her out it snowed enough to coat the subdivision streets and now it's starting to ice over. I pushed her a little hard around corners (making sure no cars where on the street ir anything I could hit was not in the way) and the back slipped out but then the front wheels brought it back to center. It seems like the 4wd is working but I don't understand the light never turning solid. I will go out right now and try that battery trick and post back with my findings. If it is the encoder motor going is there a way to check if it's good or bad? I believe it is the original but I'm not sure since I'm the thrid owner. I have a feeling that the 4wd is engaging but not fully engaging due the the light on the switch just flashing. I also noticed is that when I switch from 4H back to 2H the 4H light turns solid while the 2H light blinks then turns solid, I don't know if this is anything but I'm trying to post as much info as I can.


JP I just did that battery trick and nothing changed, but I did hear the encoder motor switch on when I connected the neg cable, I thought it was odd when I did it but then I started to truck and I saw that I left it in 4H. So that explains why I hear the motor going. When I put it it 4L I hear a loud clunk, but when I put it in 4H I just hear the motor and TCCM click, is this normal? Also, is it normal, while in 4L, for the engine to go up to about 1500 rpms at about 5mph then fall back down to below 1K then go back up at about to 1500 rpms at about 10 mph then fall back down to about 1k again? < I hope that just made sense to you guys. My 4L other than what I just said works but I'm not really sure about the 4H.