4 Wheel Drive doesn't Work

Check AC/HTR fuse first. Check for feed wire problem at transfer case switch, possible open. Also inspect wires to actuator, and inspect actuator for damage.

See the guide below on testing wiring

https://www.2carpros.com/articles/how-to-check-wiring

Wiring diagram for your 4wd system is attached below

My four wheel drive will not engage what could be problem?

Check to see if there is power to the 4wd actuator on the transfer case (if it is the electric shift). If it has the lever on the floor, check the linkage to the transfer case. If it is good, tight, and properly adjusted, check to make sure the actuator on the front axle is working. There is an updated actuator for these, the originals had issues

See diagram below

Hello my name is evan and I have a chevy 4x4 all time drive. The other day in a snow storm I went to get some gas for my truck and I had it in 4 low and it was fine I pulled into the gas station shut it off paid for the gas and pumped then started to leave I pulled up to the exit and stoped at that very secound it somehow stoped working and at the traffic light was still not working and I went home and every thing seems to be moving and I replace one of the sensors on top of the transfer case and that was good when I took it out but I put the new one in anyways tried it out and it still was not working and I noticed that there is a nother sensor on the front differential im not sure if that is what is wrong with it or not but if I get some feedback I will go buy what I need and I checked the fueses jiggled the wires and it is still not working, 4hi or 4low does not work. So if you could plz help me figure out what is wrong with this thing thanks very much. Evan

Hello Evan
I have a 94 Silverado with the same issue, mine has the automatic transmassion and the floor shift for the 4LO N 2HI AND 4HI with an indicator light that lets you know when the front axle is engaged. My indicator light is not working, the bulbs are good and so are the fuses. It is not going into four wheel drive even after I replaced the front Actuator. From what I have read this seem to be the problem in most cases for the front axle not to engage. Jack up the right side and locate the Actuator on the axle housing and remove the Actuator, do not disconect the wire connector, put the sift lever into four wheel drive and check the Actuator if it does nothing it needs to be replaced, This did not help in my case but check out the front Actuator front axle right side. Hopes this helps

My 1994 chevy silverado wont shift into 4 wheel drive

I have got a 1994 chevrolet 1500 four wheel drive pickup and have been having some problems with the four wheel drive it will not go into four wheel drive I replaced the acuator switch in it but it did not do any good it still won't go into four wheel drive checked the fuses all good and my cousin tested the wires and he is saying I am not getting any electrical current he is saying that it is a bad wire somewhere between the fuse box and the front axle the transmission is going in and my four wheel drive shaft is locking in but the four wheel drive will not go in I was wondering if you could tell me what is wrong with it

Chances are one of the wires are damaged or broken. The only thing you can do is follow the wiring to identify where the problem is located.

Hi, on my K1500. My Four wheel drive is not working. If I put it in four low it does not light up and it does not engage. When you put it in four low the unit should turn orange in the front and I am getting nothing. Four hi does not work either. I read about the actuators going bad but I am not sure if this is what the problem is. I have not crawled up under their I just had surgery Wednesday. My dad actually told me it was not working. Is their a way to test this actuator? If so I would appreciate any help. I really do not want to put in a new crank case but if I have to I guess I will have to. I just want my Four wheel drive working again. Trying to get in my backyard is a pain. The truck just about sinks to the axle and then gets stuck. Thanks for any help. I will not be the one testing the actuator. I just had open inguinal hernia and I am in no shape to lay on my back or side to mess around with this. Thanks.

Hello,

Yes two things go wrong with these cars, either the switch on the dash goes bad or the shift actuator. You can remove the actuator and then use the switch with the key on to see if it move the way it should.

Here is a diagram to help you get the job fixed.

Hope you feel better soon, my son just had that done as well. Hang in there and let me know what happens.

Cheers, Ken

Hi thanks for the response. I have the actual floor shifter I don't know if this makes a difference. This is what it looks like in 4L. It partially engages. Yeah I am doing better I had an open hernia surgery. I don't know if your son had laparoscopic surgery or not. The open hernia surgery was terrible. But I hope he is doing well. I can't get to involved. But I will try my best. Thanks. Here is a picture of what I have for 4wd. The second picture was online but it is exactly the same thing. Thanks.

Hello,

Yep sorry about that, it looks like something has gone wrong inside the transfer case. Here is an exploded view of the unit if you would like to take it apart to see whats going on. The fork slides usually wear out not allowing it to shift to 4L

Hope you feel better soon, my son recovered nicely so hang in there.

Please let us know what happens.

Cheers, Ken

So just an update I took it to a friend of mine. He is a mechanic. Their was no power getting up to the actuator. He traced the wires back to the transfer case switch. Their was no power at all. He took the switch out and when he tested the switch it was giving weird readings. He had a probe and unhooked the actuator and it powered the actuator and it worked. The 4wd light up so he suggested the transfer case switch and also the actuator. So I got both. He put the switch in then put the actuator in. He got power to the actuator. But he had to use a ground on his meter because their was no ground getting to it. After he did that it showed 12 volts. He put everything together we started it and had no luck. So he cut one of the wires on the connector that connects to the actuator plug. And he grounded it out to one of the starter bolts. Now it works. We put the old switch back in and that was bad so we just put the new transfer case switch in and it worked. The old actuator might have been good but I just wanted to replace it since I already had it. I don't know if the ground is a problem on these trucks or not. But it works now. Thanks for all the help.

Nice work, we are here to help, please use 2CarPros anytime.

Cheers, Ken

Transmission problem
1992 Chevy Silverado V8 Four Wheel Drive Automatic 199k miles

it will not engage into 4wd. I have checked the fuse and it was popped. I replace it and it pops again. I then put a larger fuse in and that pops. What could this be?

Come on, noone knows anything?

Check the wiring at the front axle electric servo/solenoid. If you have a short-circuit, it will snap the fuse. Don't keep "Upping" the fuse rating as you have tried. You will melt the wire and may cause a fire.

Runs great in 2h, but 4l and 4h won't work, it stays in 2wd.

Can u shift it into the 4x4 or wont move

anyways id first try ingauging it in different gears, be at a dead stop, and give it time to ingauge