4x4 not working

According to my wiring diagrams there are not any under the hood.

To start,I am showing two fuses. They are numbers 2 and 24. Two is for the transfer case and 24 is the for the 4wd. There is a transfer case switch at the top left of the transfer case and a transfer case encoder on the right side of the transfer case. Have you checked wiring to these items and the fuses?

From the transfer case switch in the vehicle, there is a gry/blk (for 4wd hi) wire that goes from the switch to the transfer case control module which is under the dash. Check if you can find it and see if there is power to it.

As far s the relay, it looks like I was wrong.

Both fuses are good both have power. All wiring has been checked and repaired. Will double check to make sure it was done correctly.

update, found another broken wire on the encoder now the 4wd just kicks out.... all buttons on dash work but it kicks on then it kicks out immeaditly.

Is there anyway that you can engage the 4 wheel drive without using the buttons on the dash? They are not in working order. Everything works except the buttons/switches on the dash. Thanks in advance... Paul Gates paulnvick@cableone.net

you will have to get the switches repaired as this is a motor driven system you can not over ride it.

mark (mhpautos)

So, there is no way to get it out of 4 wheel, until I change the switches? Are they 12 volt current to each: 4H, 4L, 2H ? Can't I jump the one for 2H and make it go into 2H? I just need to know which wires to jump across. I guess the most it would do, would be to blow the fuse, right? Please advise, would like to drive my vehicle. I'm an unemployed construction foreman and they want $75 for the switch at Autozone and they have to order it!! So, looking for a used one at the salvage yard, but harder than it sounds and they want $40 for it, when I find it! Would appreciate the help if possible... Thanks in advance...Paul

If you want you can fit your own switch, that will work, but just making it practicable this is your problem.

mark (mhpautos)

My vehicle will not go into 4 wheel drive. I have replaced the 4x4 switch and module. Dealer said that these are most common problems. Had a friend install and same problem continues. Any suggstions.

There is an actuator motor that puts the transfer case in 4-wheel and an axle motor that engages the axles for 4-wheel drive. Either or both of these could be bad...This is common also..

Tires and Wheels problem
1995 Chevy Tahoe V8 Four Wheel Drive Automatic

how do i engage 4x4 on my 1995 chevy tahoe?

Pull the level on the floor (under the dash, between the drivers and passengers seat) to 4X4. This can be done while moving. If stopped, it will take a few revolutions of the tires to engage the 4WD.

If you want 4X4 low, you will need to place the transmission in Neutral before shifting to 4X4 low.

My 96 Tahoe does not engage the 4 wheel drive. The light on the 4 wheel drive just flashes but it sounds like the transmission is trying to shift into 4 wheel.

It sounds like a bad actuator on the transfer case. Also, have the computer scanned for trouble codes.

I have changed the 4x4 swicth that goes in the front axel and it still is not working ! what else could it be , What would make the four wheel drive not work ?

There is an actuator motor on the transfer case that engauges the 4-wheel drive. There is also an actuator motor on the front differential that engauges the front axles. It could be either/ or / both of these things.

Eeesh!
Looks like they’ve merged several conversations and now it’s all gobbledegook!

Yep it got merged, what is the problem again?

Here goes again:

I have a similar problem.
1998 Tahoe (on small island of Guam so parts are hard to come by).

I use 4x4 allot getting boat out of the water. It was working fine until last week when it stopped working.

After reading your thread, I found that my #2 fuse was also blown. I replaced an 4x4 worked immediately - once. Now I blow a fuse every time I replace the fuse and the engage the 4x4!
I've just let the truck in 4x4 mode and so far haven't blown any more fuses and the 4x4 is working. The problem seems to arise when I switch out of 4x4 and back in.
I'm also pulling a trailer that is submerged in saltwater. All the lights work and it was not causing a problem before - but could be a short?

Help?

Yes, I would unplug the encoder (actuator) and then replace the fuse. Work the switch etc., to see if the fuse blows if not replace the encoder here are diagrams to help. #20

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

Hi. Sorry for the late reply.
I switched the truck out of 4x4 and it went back into 2x4 no problem.
Again when I switch back to 4WD the fuse pops.
I’ve unplugged the actuator (as suggested) and the fuse still pops the moment I put a new (20 amp) fuse in (actuator unplugged).
I put in a 25 amp and it popped the first time, then held the second time. I plugged the actuator back in and has allowed me to go back in to 4x4. That suggests the actuator is still ok and the short is elsewhere?
Also, the lights of the rocker switches are lighting up ok, but then they go out once it’s in 2x4 or 4x4 or are intermittent.


Other suggestions appreciated. Thanks.

Also,
When the fuse blows the lights on the rocker switches display an odd lighting scheme - image. Three lights are lit. The 4x4 low, the 2x4 and a red neutral light is indicating! This is when the truck is now in 2x4 and the fuse is blown.

Help.

Thanks.

It sounds like the rocker switch is shorting out, lets try a new one to see what happens.

Hi. Sorry for long delay. Takes two weeks to get parts out here in the middle of the Pacific.
So, replaced the rocker switch. Nice to see 4x4 and 2x4 actualy light up, but unfortunately still popping fuses. That is, when I switch from 4x4 back to 2x4 it switches but then the fuse (number 2 pops).

To date I’ve tried unplugging the actuator and rocking the switch (pops fuse) and replacing the rocker switches (still pops fuse).
As above, when the fuse pops, three lights are lit. The 4x4 low, the 2x4 and a red neutral light are all indicating.
When I replace the fuse, it immediately pops a new one (20 amp). I have then placed a 25 amp fuse and sometimes it holds and I can switch back into 4x4 where it will hold for weeks - until I switch back into 2x4 and the pop! All the fun starts again.

Any further suggestions of what I can test?

Thanks for your patience.

Down at the encoder can you unplug it and then replace the fuse to see if it still pops?

I think we did that already. I have unplugged the encoder and pushed the rocker switch and it still popped the fuse.
I have not done that again with the new rocker switch and will try that.

Okay. When the actuator is unplugged the fuse still pops when the rocker switch is pressed from 2x4 back into 4x4. This is the same weather the actuator is plugged in or not.
That would suggest the actuator is still good and I have just replaced the rockers switches. So it’s good.

What else to test?

Thanks.