Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Blazer Jimmy 4WD Questions



  • i can push the button in my 97 Jimmy and i can hear a and feel it shift into 4 wheel drive and then when i hit 2 wd button i hear it and feel it shift back but its not working when i look are it if i get stuck the 4 wd dose not engage but the buttons light up and i can hear the noise what coudl this problem be and im not able to fix it myself how mouch could the most a shop would charge me cost do you think
    thank you
  • repairdogrepairdog Posts: 948
    Search in the forum for many posts on this.
    Basics is you have to go thru the vac system and 3 port vac switch on the transfer case, the encoder motor on the case, the vac actuator under the battery, the front axle coupler, and the TCCM (4wd PC) to resolve. Vac lines and 3 port switch are where to start - see if all good and not rotted/split.
  • grose67grose67 Posts: 5
    I had the type of issue happen on my 95 Blazer. What I found was a kink in the vacum line. Once that was fixed, the 4 wheel drive worked great and has ever since. That was two years ago.
  • gregg67gregg67 Posts: 1
    i have a 2001 blazer that is stuck in wheel says its in 2 wheel.i'm pretty sure its HI you can hear it switch to LO and feel the difference.any ideas and how to chek servo's,switches etc; would be greatly appreciated.
  • my blazer is stuck in 4WD Hi. Everything worked just fine until I put in a new heater core (what a job that was!) The heat works great now, however, upon starting it back up it is now stuck in 4WD Hi. When I try to switch to 2 Hi, I can hear it trying, but it isn't switching over. Any ideas on where to start? I know it is electrical in nature... i'm thinking that i just bumped a wire some place when i was in the dash, but don't know where. Any help would be GREATLY appreciated!
  • I have a 98 Blazer I bought a few months ago... I have been getting very frusterated trying to figure out this problem.

    The truck feels like I'm towing a trailer all the time, however the odd time it seems to lighten up. All the bumps on the road are very hard, very rough ride and when I go over bumps it bounces all over. Now when I put it in 4WD and hit the gas, I hear a cluck from the front left wheel. It almost sounds like a CV joint on a FWD car. But louder and harder.

    I feel like these problems are all related to the same thing, but I can't find it. I've checked if any of the brakes are draging there all good. It possibly needs an alignment. If anyone can help, please do before I sell this thing!

  • Push button to 4hi, it blinks for a few seconds and goes back to 2hi same when trying to put in Auto 4wd, any help would be appreciated.
  • Don't know if it helps, but I just had the same problem except none of the lights were on!! I took the dash completely out to find out it was a wire had broke going into the harness!!! I just snipped the other side and now it works fine!!! I also had a couple wires that were pulled out of the harness just far enough that my fuel gauge and my temp gauge would not work so i just took a screwdriver and pushed the wires in just a ittle to were they were working!!! Hope this helps!!!
  • Can you here transfer case motor trying to shift, if so then it could be inside the case its self, this is the problem I have now. I can here the motor trying to shift into 4Hi but it would not go, $200 new motor and it still would not shift. I found you should be able to remove case shift motor and you can shift it with a wench with little effort,if all is in good working order in my case it dose not! So i will be removing that part next.the button tells your 4wd controller what you want it check to see if the motor dose what it is told if it dose not move it tells you that nothing is happing.the hole thing is a pain in the...., when it don't work.
  • 4X4 stuck in 4L, constant ticking under pass side dash, replaced 4X4 switch on dash, disconnect batt, still doing same, starts ticking appx 30 secs after key is on. Any ideas, please help.
  • Need to know if you can here, transfer case motor trying to shift ,you should here a noise right under the center console . there is a drive motor that is turned on by the dash switch, the clicking you here on the passenger side is a relay that powers the motor. I think if you can here the clicking that the dash switch is not the problem. if the relay is good then you should get power to motor on the t.c. I found the motor to the T.C. was not that hard to change About a 40 min job. remove front driveshaft {4 bolts}.then you unplug motor and it comes off with [3 bolts]. Then you take that to local auto parts to match , because there is three different motors and nobody witch one you have. with motor off you can shift T.C. with a wrench, there is four positions 2hi 4hi N 4l you will have to shift to 2hi to install new motor, if you cant shift you can try to move rear wheels to line up gears, or you could have T.C. internal damage.hope this helps.M.C.
  • Thanks and yes motor is working I actually found the problem and fixed it a few minutes ago. I started with the actuator under the battery (actuator was in good shape) checked all the vacuum line going to vacuum switch under hood seal (those were also in good shape). Then I had a friend hold the elec. switch on the front differential pulled out the switch tried to put in 4 wheel same thing it just blinked compressed the ball on the switch and the light stayed lit so we went back to see if the actuator was actually moving and no so we went back to vacuum switch under the hood seal ordered the part from GM (they call it a valve) put the part in and it worked. $50.00 for that I brought back the actuator which I didn't need that was $59.00. Hope this helps you or anyone else.
  • have 2003 blazer 4x4, no major problems, except bad gas mileage, was driving on ice decided to switch into 4 wheel drive hi, pushed button, it is 4x4 on the fly right? running 35 mph, pushed 4x4, got funny grinding sound, acted like didnt want to go anywhere, grinding, loud.. under blazer, so when heard the sound, pushed in rear wheel 2x4 and still had sound, slowed down to 15 mph, and pushed in 4x4 low, still had the grinding sound, then pushed in normal rear wheel drive, and must have hit a bump but felt a tug of the vehicle and a loud bang, and then it started driving fine again, needless to say, wondering why it happened and what it might have been, haven't used 4x4 since...could it have been frozen?, it was 15 degrees that day..took it in about 4 months ago to jiffy lube and they changed the rear differential fluid...could it have been something they did? thank you in advance
  • you should try the 4x4 again , well in park,it should shift,and not grind because your not moving, if it dose shift, then try to drive if you here noise than you got trouble. The rear differential drive all the time two or four wheel drive, so if it was in that area you would have know it long before now. you could have lost your front drive shaft or you have problem in you transfer case.hope this helps.
  • ok my 95 Blazer LT has 4WD but when i push the button on
    the dash for 4WD it lights up but it dont feel like its in 4WD
    and its not. What may be wrong and how would i fix it? im
    thinking maybe the vaccume sensor may be bad...

    Also i would like to raise it up a bit but since the leaf springs
    are under the axle its more dificult. all i need is some
    sugestions on the cheeper better stuff to get to get the
    height up the most.

    Charlie Armstrong
  • ok well i checked the vacume lines and one was bad...
    fixed that and it still dont work any other sugestions

  • This is my daughters 97 Jimmy v6 auto. The 2wd button does not light, the 4wd buttons do. I hear the clicking under the dash. 4wd will not engage, but when I try to go to 2wd I hear the right front grinding. It recently had the heater core replaced. I removed the battery connection for 30 minutes, turned on/off 5 times. No changes. the plug on the back of the dash switch seems tight but I reseated it anyway.

    Any help nailing this down is appreciated since I have the flu and don't have much energy to trouble shoot every single point if I don't have to.
  • Small update. I have since pulled the TCCM plug and cleaned with WD40, pulled the battery/tray and the vacuum module under the tray doesn't have any broken lines to it. I'm not sure what to do with the battery in order to test it while the engine is running. I followed the vacuum lines to the area of the distributor/trans dipstick tube. I could see where it went down to. I did find one vacuum line by the power brake unit plugged with a screw. I attached it to the round black vacuum bottle on the hood. No changes. I may take it to a shop tomorrow since I didn't want to get under it today (cold, wet). Any additional ideas welcome. Thanks.
  • Shifted into 4hi yesterday morning. Felt the 4WD engage. Immediately after, all of yellow 4wd indicator lights on the 4wd push buttons shut off. After driving for about 2 minutes the light on the 4hi button came back on. Now it is stuck in 4hi. I have pushed the 2hi button multiple times and nothing happens. Any idea what the problem could be? Any help would be greatly appreciated. Thanks.
  • i recently received a 95 blazer for my daughter. it needed a little here and there, but in decent shape for age and miles(265,115) and obviously the 4wd didn't work. I have been trying to be a good mechanic all my life 30+ yrs. feel i know quite a bit, but as any good mechanic would say, not everything. i am always open to listening, and reading,etc. I knew coming to this forum area I would be helped by reading complaints that are consistent to mine. i must give an open thank you to everyone who participates in these forums. a mechanic knows that you can't keep up on every model or every problem, and i've worked on my share of blazers/s- trucks, but not everyday. so reading the posts here refreshed my memory on the what, where, hows, etc. for those who are searching for the cure of no 4wd, my solution was completely checking all electrical connections, all vacuum hoses including the 3 port switch on the transfer case underneath. take the time to check it. the three hoses eventually route up over the top of the transmission and are assumed to be protected from the elements, but one of them i found was bad. also one at the actuator was cracked. also all from purge canister (black ball drivers side). also do not overlook the main line from purge goes to a main port on backside of intake just left of distributor. that one is hard to see, but if its disconnected you will not have 4wd.
    all my babbling comes to this...
    i got this truck from a relative. was told the 4wd never worked, and they had it for approx. 9 yrs. i took a couple hours of my time, traced every possible vac line, elec. connector, got dirty,
    but my daughter has a 4wd that actually has 4wd.
    my complaints were consistent with everyone elses
    but by taking the time to read everything i could find here, it helped me cut hours and possibly dollars off the whole project.
    as an old timer once told me, "If you don't learn something new everyday, your not paying attention in life" :shades:
  • Just to had a question to your checks.When I checked the purge canister under the hood I found that it was about half full of hyd oil. Any idea where it accumulate from and what would be the fix?Nobody I've talked to so far has any idea including the local GM dealer.
  • was it trans oil or motor oil? if it was motor oil, I could see possible reasons for that. is your transmission at proper level of fluid when it is hot? if it was over filled you might have certain problems with that. is it a good runner, or does she have a few miles on her? does it smoke or use oil?
    if the trans is seriously over filled, or you are experiencing "blow by" in the engine, you could point finger in that general direction.
    I've seen oil in vacuum lines before, but usually the trans level, or oil level was too high , or blow by existed because of either worn engine, or non-maintenance of emission systems
  • It was deffinitly tranny oil. Oil levels are all good It has 250,000 kms but other than a few electrical problems it is a good runner. I try to keep everything well maintained but sometimes we get busy and maint schedules slide.
  • yes, no fuse means no cruise... check the wires for the ABS on the new bearings, this is what causes that ABS problem... I had it twice, once before replacing the bearings and the 2nd time I had a broken wire leading to the ABS box... you may need to pass a dealer to have the computer reset on the ABS once this is fixed... good luck.. BTW if the bearing are not GM AC delco this can also be your problem, the first set of bearing I got, just didn't work with the ABS system and had to be replaced a 2nd time.
  • I have a 97 blazer LT with the 4wd, only i don't have the buttons to swap from 2 to 4 wheel... I wanted to know if this option can be added and what changes would have to be made to do so? anybody done this already?
  • My 1995 Chevy S-10 Blazer will not go into 4WD. The 4WD is electonic with a button for 2H, 4H, and 4L. When you hit the 4H button, the light comes on and you can hear the relay in the control module in the dash activate. I can also hear the tranfer case motor engage. The drive shaft to the front differential is also engaged. I have replaced the vacuum switch on top of the transfer case (ball inside was sticking). I am not getting vacuum to the vacuum diaphram actuator located under the battery tray. This is what engages the 4WD. I have checked all vacuum hoses for breaks or kinks. Where does the vacuum hose go after it leaves the actuator? It appears to go in behind the motor on the back leftside as you face the motor, but cannot see where it connects. Does anyone have or know where I can get electrical and vacuum diagrams of the 4WD system?
    Are there any other items that can be checked? Thanks.
  • gmc94gmc94 Posts: 4
    Hi i recently bought a used 1994 GMC Jimmy and i have some problems with the 4-wheel drive switch. When i goo into 4-wheel high it will not let me i can feel the gears trying to switch but it doesnt work, but when i switch it into 4-wheel low it works perfectly i dont know if i should replace the switch or it has somethin to do with the transfer case itself can someone help me
  • Hi,

    I have recently acquired a '99 Blazer w/ 3 button electronic 4WD. It has almost 190,000 miles on it and has already become a money pit. I've replaced the transmission and torque converter, intake manifold gasket and both upper and lower ball joints in a 2 month period. Now I'm concerned about the 4WD. When I got the truck the 4WD worked fine..shifted on the fly smoothly no grinding. After I got it back from the tranny/ torque converter work there was a nasty grinding when i put it into at 50mph and was told by the mechanic that did the transmission work that I should always be stopped and in Park or Neutral to put it in 4WD regardless of what the manual said. That seemed to be fine but last night (I live in Michigan with lots of snow right now) I put it in 4H just to get it into the driveway and when the tires started spinning there was a terrible grinding from underneath. I am still able to move it from 4H to 2H (haven't tried 4L) and it seems to drive fine in either with no grinding unless the tires spin. Any clues would be greatly appreciated. I have put almost $3500 into repairs on this truck (which is more than I paid for it in the first place last November).

  • I have the same problem. Talked to mechanic, suggests there is a small motor that switches the 2wd and 4wd. I'm taking in my car in 1-2 weeks..I hope that fixes it.
  • Where is the "vacuum switch under the hood seal" located? I am not getting vacuum to my actuator located under the battery tray. I have checked all the vacuum hoses and all are o.k. Do you know where the vacuum source is located ? If I connect a vacuum source to the actuator I can get the 4WD to operate. I have what looks like a sensor that is located between the battery and the coolant reservoir and is mounted on the fender well. One end has an electrical connector and the other end has a vacuum hose on it. Is this the switch you are refering to? Thanks.
Sign In or Register to comment.