Four wheel drive not working

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 what's going on. The fork slides usually wear out not allowing it to shift to 4L. Much better chance it's the thermal actuator in the front axle! Much cheaper and very very common! That's what lights up the shifter console also. Still engages the transfer case just that the front axle doesn't engage. Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

So just an update: I took it to a friend of mine. He is a mechanic. There 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

My 4 wheel drive isnt working on 1993 chevy truck. I was looking at it and found the wiring from the transfer case is not plugged into anything.I dont see any open plugs. I was hoping you could tell me where it plugs in

There are two different types borg warner and New venture. Do you know which you have? The first pic is a new VEnture and the 2nd a borg warner. There are 3different types of borg warner and 2 different types of newventure but the electrical shold be similar in each case

I have a 4 wheel drive that will not work. I have changed ther electric modulator and it is still not working. I double checked it also to see if the plunger on it was relasing and it IS releasing all the way. I also checked all the electrical fuses to see if it was an electrical issue. All is fine. The front drive shaft is also turning so now what could it be? Any ideas? Thank you

Are you saying that the transfer case is working but the front axle won't engage?

Hi, I have been reading about four wheel drive actuators and transfer case switches. I have the truck listed above Scottsdale with a 6.2 diesel and a manual four wheel drive shift on the floor, by the five speed shift. The four wheel drive is not operating and I have seen reference to the vacuum lines. How is the vacuum involved in this four wheel drive? My vacuum pump is operating correctly.

Hello I am Danny,

I have attached a few pictures that include a description of how the actuator engages your front differential when put into 4x4 mode. This is an electronic actuator and is not vacuum operated. In the picture I circled the actuator in red. These actuators are prone to failing. Hope this helps and thanks for using 2CarPros.
Danny-

Thanks Danny. I ordered a new actuator.
On a different subject:
I would like to repair my blower motor resistor by replacing the thermal fuse but I can not read the writing on the old fuse. I think it is 228 degrees Celsius but it is quite worn off. Do you by chance know which replacement thermal fuse I should use on the blower resistor?

Hello RAYDAVIES,

You are asking a new question regarding your blower motor. In order for the site to index your question please post your new question here:

https://www.2carpros.com/questions/new

Make sure you are logged into the site before clicking on the link.

Thank you,

Renee
Admin

This is very strange, I have replaced my 4x4 actuator about 2 years ago because that was causing the 4x4 to not work at all. But after I replaced it, if I have been driving for a while or it is HOT outside the 4x4 will not engage. Now if it is cool outside and I haven't driven anywhere, or it is the first start up for the day and everything is cool-cold then the 4x4 will engage and work fine. My Question is WHAT THE HECK IS CAUSING THIS?
Really Frustrating. Could I have gotten a bad actuator, or what else could be the culprit? Really frustrating when I have been riding for a bit and then I NEED the 4x4 and I am plain ol' STUCK. Please help

They have since updated the actuator because they were having so many problems with them. When it is inop connect a test light between the 2 wires of the plug that goes to it. If it lights you have another bad actuator. Also there are thrust washers in the front diff that wear out and can fall causing the front diff not to engage. If the actuator tests out ok then remove it and try to push the actuator in the front diff in while spinning front wheel and see if it will engage.

Do you mean remove the actuator and try to push in the hole the actuator threads into with say a wooden dowel and spin one side and when they both engage then its teh actuator? Do I do this with the transfer case in 2H so the Front drive shaft will be able to rotate when engaged by the dowel? I just went outside and started the truck put it in 4H pulled foward then backward and it went into 4wheel drive. The problem is when the truck has been driven for some time? Still puzzling? You think the upgrade to the DORMAN 600-101 actuator would help?

Updating the actuator wont hurt. They are known to be bad. Also yes I mean take the actuator out and push in with a dowel. Leave in 2wd and just see if it engages.

The 4x4 engaged everytime I tried today! Again before I really travelled far. I went about 10 miles then gave it a shot. And it worked, it seems so strange? I was reading something about the Four Wheel Drive Selector Switch that is on the transfer case itself, could I have a faulty one of these that is intermittently working? Are they easy to change out? Could I have a corroded one that when it gets hot (from transmission heat etc) not send the voltage to the actuator? Not sure where on the transfer case it is located. Really appreciate your insight.

The transfer case is connected to the rear drive shaft. The selector switch in located in top of it. Using a 7/8 wrench you can remove it.

My four wheel drive dont work when I put it in four wheel drive. I checked the fluid and it is good.