4 wheel drive is not responding

There is three fuses that run the 4 wheel drive system. Here is the wiring diagrams so you can see how the system works I would test for power at the fuse and at the transfer case controller.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (Below). Please let us know what happens.

Cheers

i switched up all the relays and fuses nothing

Then we need to move back to the switch. Are you getting power to it?

ok when you move the switch no lights come on at all like the light is supposed to come on and tell you what drive its in right but the words light up when the headlights are on but there is no lights on the top no at all indicating im about ready to just give up on this pos

There is no power getting to the switch. I just looked at a schematic of the system. According to the schematic, there is a 15 amp fuse in the rear fuse block below the left rear seat. Did you check that? Also, under the hood at the fuse block, there is a black / white wire which is a ground. Check to see if it is in good condition.

I have attached a schematic. Even though you can enlarge it, I don't know if you will be able to read it. Let me know if you checked there for the fuse.

Electrical problems can be a pain so I understand your frustration. What even makes it harder for me is not being there. Hang in there, and we'll get it figured out.

Joe

the fuse is good in the rear and same with the ground wire no corrosion still nothing. i do really thank you for helping me through this. i wish i had a car lift make it easier to get under it instead of jacking it up then climing under it lol.

I'm glad to help. I just wish I could make it easier for you. Is there power to the rear fuse? I ask so we can limit the number of things that need checked. Something tells me we have a broken wire between that fuse and the switch.

i did the light test for power i dont no if it check to make sure the fuse is good or if there is power. i have the power tester but i dont no how to use it :( i can have my neibor check it for me he nows how to use one. i hope theres not a broken wire. ill let you know what the resolt was on the rear fuse im going to have him check all the fuses to the 4x4 maybe im missing something and used the wrong tester.

Not a problem. Let me know what you find. It sounds like the transfer case controller is out here is its location tey a used one.

Joe

Thanks for the tip I got s used one from my buddy who has a bunch of parts for these cars and it worked! I am ready for the snow. :) thanks again

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers

had to lock it in 4 wheel drive yesterday it whent in fine and got me out of the muddy parking lot i was in. flipped the switch to go back to 2 wheel drive and the warning light on the dash came on the one with the wrench beside the drive train and the lights that indicate what it is in 4 high 2 high and such blinks for awhile in each position and then completly goes out. the next day light was out when i started it and the light blinking for the 4 wheel drive selector did the same thing now no light on 4 wheel drive selector and light is staying on on dash. HELP HELP HELP

Chances are there is a problem with the actuator on the transfer case. Have you checked for power to the actuator?

The range switch won't put the trans into the 4x4 LOW range - it switches back and forth between 2WD, AWD, & 4x4 HIGH, but won't shift into 4x4 LOW - the light just blinks then stops and the 4x4 HIGH liight stays on - HELP

Put the transmission shifter in neutral. Then, try and shift into 4WD low. The transfer case won't go into 4 low unless the transmission is in neutral.

[quote:44f16eda5f="dennyp"]Put the transmission shifter in neutral. Then, try and shift into 4WD low. The transfer case won't go into 4 low unless the transmission is in neutral.[/quote:44f16eda5f]

I've done that - I have 71K miles on it - bought it new - never had a problem getting into 4x4 low - it tries, light blinks, but never shifts... like the solenoid is stuck or somthing...

You will need to remove the encoder assembly and manually try to shift it into 4 low. If it goes in, your problem is in the encoder circuit. If not, you need to teardown the transfer case for inspection.

The stabilatrak light occasionally comes on and stays on (not during a traction problem). Shutting the vehicle off and turning it back on clears the problem. What could be causing this? Also the other night due to icy and snowy road conditions I switched the 4WD switch from 2H to Auto. The auto light blinked for an extended period of time and then went out. I tried other modes and the same thing happened. No indicator lights for any of the drive modes were on, but a red N was on next to the 4L position. I have never seen this before. The vehicle was in 2H and seemed to work fine. I shut the vehicle off several times and restarted it but none of the indicator lights were on and the red N was still on. I continued to my destination. I was there about one and a half hours. When I started my vehicle the 2L indicator light was on and I could change my drive mode. Looking for answers to what caused this and remedy for both of these problems. Are the two problems possibly related. Also does the red N indicator normally signify the transfer case would be in neutral?

scan for codes first see why it doing what it is.

Scanned for codes. There are no codes stored.

if you scanned for codes with a typical auto parts scanner these codes won't show up. you'll have to have a pro scan it for you. this may be a trans module problem or an actuator for the tcase but the stabiltrak has to deal with the abs system.

Hi, I have a 2006 Trailblazer (Extended) with 4 Wheel Drive. It works great in 2WD or 4 Wheel High. However, when I set it to "Auto" and I drive up a hill, something seems to "Slip" / "Clunk" about every 3 seconds. I took it to the dealer and they "could not find anything wrong" and asked if I was driving on Ice or in wet conditions. I have tested it in completely dry conditions and it always portrays the same symptoms when driving up a hill. What is likely the issue?

sounds like a worn clutch pack in the transfer case.

might want to look at this bulletin,just went throught this at the shop.Subject: Misfire Bump or Multiple Bumps after a 1-2 Upshift


Models: 2004-2007 Buick Rainier

2002-2007 Chevrolet Trailblazer 4WD

2002-2007 GMC Envoy

2002-2005 Oldsmobile Bravada

2005-2007 Saab 9-7X

Equipped with All Wheel Drive RPO NP4 or 4 Wheel Drive RPO NP8 The condition can be perceived as an engine misfire, surge or bump typically during or just after the 1-2 upshift. This condition can occur on Bravadas, 9-7X's and Rainiers NP4 Full time AWD. This will only happen in Trailblazers and Envoys NP8 when AWD (auto mode) is selected. When viewed through the TECH II, misfire counts may be occurring but not enough to set a misfire DTC. The concern will be eliminated in Bravadas and Rainiers with the ATC fuse removed or in Trailblazers and Envoys when 2hi or 4hi is selected.Inspect tire pressures and adjust as necessary. Swap the wheels and tires from another identically built vehicle that does not exhibit the concern. If swapping the wheels and tires does not improve the condition, drain and fill the transfer case with AutoTrac II fluid and re-evaluate the condition.

This is likely a characteristic of the vehicle and some degree of this condition should be expected on all of these vehicles. Comparing this vehicle to an identical vehicle with similar mileage should verify this is a design characteristic. the dealer should have looked at this bulletin and tried this first to see if the problem went away.

Hi, I'm Alessandro, and I write from Italy.
I have a 4.2 ltz trailblazer from 2003, and I have a problem with the 4x4 switch. In Italy it is difficult to find good mechanics for American cars, and before making empty attempts, I would like to ask for advice here.

The 4x4 switch lights only come on when I start, while driving is off, if I try to insert the 4x4 this doesn't work, unless I turn off the car, set the switch to 4x4, and turn it back on, in this way I get all-wheel drive.
To return to the two-wheel drive the same system, I turn off the car, set the switch to 2h and restart the engine.
Has anyone ever experienced the same thing? and if so how did you solve it?
Thanks for help...

Hello,

There are two fuses (ATC and IGN1 under hood fuse panel) we must check for power. here is a guide to help us get started and the fuse locations along with the transfer case wiring diagrams so you can see how it works below:

https://www.2carpros.com/articles/how-to-check-a-car-fuse


Check out the diagrams (below). Please let us know what happens.