Blazer 4 wheel drive problem

Farmington, KY

#41 Nov 16, 2009
Mark S wrote:
I have a 1996 chev blazer. Driving down the road, the 4 wheel drives appears to want to engage on its own. If I click on the 4 hi and back to 2 hi, the noise quits. This is happening on a regular basis by hearing a loud humming noise. Is this something with the switch or what else?
I'm having the same trouble. I replaced a worn gear and a spring in the axle housing. Still makes the noise. Also, even when it says it is in 4 wheel hi or lo, the front wheels will not pull, but the noise will go away when it is in 4 wheel. I've replaced about every vacuum line on the dang thing. The actuator seems to be doing its job. The one thing that I still suspect is the cable that locks in both axles. Mine has a hard spot in it. You can pull it by hand about a 1/4 of an inch even after the actuator has pulled it to keep it in 2 hi. I think that could be causing the hard to describe humming noise while in 2 hi. I do not know why the front wheels won't pull in 4 wheel.--I fear the worst. Any input on what to check would be GREATLY appreciated.

Saint Peters, MO

#42 Nov 20, 2009
Mine did the same thing an it was a vacuum hose that had come off. My husband fixed it and it worked just fine. Now though I am having trouble with the service light coming on and the light on the switches going off. It usually does this for about a day or two and then goes back to normal. Any suggestions?

Kanata, Canada

#43 Nov 24, 2009
1996 blazer 4x4 button flashes 3 or 4 times then goes back to 2 wheel and doesn't engage .
any ideas??

San Josť, Costa Rica

#44 Dec 5, 2009
I have a similar though slightly different problem with my 1999 Chevy Blazer LT with 4WD:
- often when I first start the truck ALL the lights on the dash mounted transmission switch are lit up (instead of just the 2WD)
- then after I drive a short distance the lights will all go out except for the correct one, ie the 2WD
- when all the lights are on the transmission feels like it has little power or torque, ie when gently accelerating it doesn't respond immediately and sometimes the entire truck has a slight shudder or vibration.
I live outside the USA in Central America and am trying to buy all the parts I may need to repair my beloved Blazer, but my jungle mechanic thinks I only need the dash mounted switch replaced. I doubt this will correct what I suspect is a more involved problem, and I'd rather ship down parts I may not need rather than wait weeks for a second or third shipment of parts as we go through a painful process of elimination. Anyway, before I ship a dash mounted shifter switch down, I at least want to see if there are other small parts I may need to replace before finding the entire transfer case needs replacement.Ugh!!
Any advise is greatly appreciated!

Williamsburg, VA

#45 Dec 9, 2009
My 94 sonoma will not go into 4H but it will go into 4L. Tried the battery disconnect thing and it worked went in to 4H. Tried again later that day and it would not go into 4H again. What could that be????

San Josť, Costa Rica

#46 Dec 9, 2009
TEST - this is a test to see if responses are posted and retrievable.

United States

#47 Dec 9, 2009
I have a 2002 ZR2 and with the first snow fall of the year I tried to use the 4wheel with no luck. I tried the auto 4x4 and the light blinks but nothing and it goes back to 2 Hi. Same thing with 4 Hi and 4 Low. lights blink but no 4wheel. Does anyone have any suggestions?
brian bauer

Faribault, MN

#48 Dec 10, 2009
I have a 1998 blazer and it dose the same thing. i havent played with it much but when i put it in 4hi it makes a loud nois in the frunt passenger tire like something is broke or loose. to get it back to 2hi i have to play with it a lotlike backing up while pushing the button. my uncal said to try jackin the frunt end up to take the presher off and try pushing the botton for 2hi.i dot know what it is.
ray-ray wrote:
my 1998 blazer is stuck in 4 wheel and it wont go into 2 wheel!!! It will switch from 4HI to 4LO, but jus makes a clicking noise and the light flashes when i try to put it in 2HI. i disconected the battery and plugged it back in but that didnt work. Any suggestions???
Mark S

Albany, GA

#49 Dec 11, 2009
The mechanic finally figured it out. The module located near tha battery was sticking and needed replacing. Minor cost for repair. It appears to be working fine now.

Westport, CT

#50 Dec 12, 2009
Thank you! I have a 2001 4x4 and my light to my four wheel drive switch would just flash if I tried to put it into any 4x4 mode. Its been like that for 3 years now. guess im kinda lazy. It was just the vacume line on the center of the firewall. now it works great. thanks to all

United States

#51 Dec 13, 2009
i have a 98 s10 blazer an i have 2 hi an 4 lo but no 4 hi any ideas

Abingdon, MD

#52 Dec 19, 2009
2001 TrailBlazer (4WD problems)..... Service 4WD light on dash was lit, read this forum and others, checked the TCCM for corrosion, was a little, cleaned it up, sprayed w\ contact cleaner and reinstalled connector plugs. Reinstalled TCCM, service light went out. All 4 lights come on briefly when key is turned then all but 2WD go out. Thinking I had the problem solved (Service light went out) I set out for a little drive in the snow, NO 4WD!!...... then the service light came back on. When attempting to switch to 4WD (HI, LO or Auto) the lights do not flash at all. I checked for a click in the TCCM, no click. I checked the vacuum hoses on the switch (located on firewall), seemed ok. At this point I am at a loss, I know of no one with a Blazer \ TrailBlazer to borrow a TCCM, too much money to guess, I have read here and other forums where people have purchased new \ used TCCM only to find that is not the problem. Please post some suggestions if you have any. Thanking you in advance........ By the way, I am stuck at home, we already have a foot on the ground with another foot on the way, and worst of all, football game tomorrow, none of my fellow game goers can come to get me.........PLEASE HELP!!!!!!!

Bronx, NY

#53 Dec 20, 2009
if the 4x4 lights keep blinking and doesnt engage to 4 hi or 4 low i would check all the vac hoses......and if you take the battery out and the battery plate under the battery you will see a rubber bladder that might have a tear in it....if thats the case replace it and the 4x4 should work fine.....i did this on my 2001 chevy blazer and it works fine now

Mannford, OK

#54 Dec 25, 2009
i have a 98 blazer 4x4 but 4 wheel drive dont work i put it in Neu push the 4lo button it flashes for a sec then the light stays on like it is suppose to you can feel it engage but not drive in front tires i got it stuck in the the snow and my wife pushed the gas and you can see the front driveshaft spinning but the tires wont any ideas

Brampton, Canada

#55 Jan 4, 2010
I have a 2000 ZR2 Blazer and my four wheel drive is not working. When I try to put it into 4 wheel drive the buttons just flash and will not engage into 4 wheel drive. However, the 4 wheel low button will transfer the rear diff into the low gear in the rear but nothing in the front.
It was suggested that I should try and find a new transfer case module, which I did, and was told that compatible part to mine (15040103) would be part number 15154323. I installed it, however, the problem has not yet been solved.
Does anyone have any suggestions? Many thanks.

Hyde Park, NY

#56 Jan 4, 2010

United States

#57 Jan 5, 2010
2000 s10 blazer, lights work on 4wd and you can hear it engage at transfer case, but still no 4wd...could I possibly need new hub bearings?

Allegan, MI

#58 Jan 10, 2010
I have the same problem as ray-ray, i did the battery thing and it worked the first time. my only problem is i will be driving along and the button lights will start flashing and then it goes into 4 hi and i'm not even touching the button. this has happened to me three times and now it it stuck in 4 wheel again. I can go from 4 hi to low but it won't give me 2 wheel. any ideas??

Summerville, GA

#59 Jan 13, 2010
Ken wrote:
Seems to me like no one read there owners manual. To get your truck into 4wd low gear "First put the truck in neutral, then press button, then gear into park, then into drive or reverse" From 4wd low to 4wd high
"Repeat" But press the 4wd high or 2wd button.
Now most of you should be able to just press your 4wd high from the 2wd and it should work.
yeah that say to do it that way if it does not work just buy pushing the button you only do that if is not working right that is to adjust it

Summerville, GA

#60 Jan 13, 2010
yeah that say to do it that way if it does not work just buy pushing the button you only do that if is not working right that is to adjust it

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