Chevy automatic 4x4 actuator/selenoid?

[shadygrady]

In my 89 1500 4x4 my front wheels are not engaging whrn I put it in 4 high or low.You can tell its going into low cause,well you can tell.It also fells as though its going into 4 high by the way it drives.The wheels just dont have power going to them.I thought it may be the transfer case not engaging so I had a friend of mine drive it slowly while it was in four wheel drive.I layed on the ground next to it and the front driveshaft going to the front axle from the transfer case was turning.Iput it in 2 wheel drive and the driveshaft stopped turning.So it seems to me that means the transfer case is engageing but the front axle isnt for some reason.I`ve read and heard that the front selenoid or actuator in the front axle is notorious for going out on these trucks.what does this sound like to you fellas.The only place I`ve been able to find the part so far is the dealer and they want about 150.00 for it.Anybody have any experience with this.Thanks in advance

[436'd skylark]

well there is a 4x4 fuse for the actuator. its a thermal actuator, most of the time the actuator gets so hot it melts and shorts out. check the fuse, then pull it in 4x4 and see if there is 12 volts going to the acuator. if the fuse pops right away, then its a dead ringer for the actuator.

[shadygrady]

I already checked the fuse and it`s fine.I guess I could pull the actuator and inspsect it and check for 12 volts going to it.Does this sound like what it may be or possible axle/transfer case problem?

[junior3382]

No, does not sound like a transfer case problem. BUt I am curious, does this have manual locking hubs or actual auto locking?

If it turns ut to be the actuator, and it is only 150 bucks that does not sound too bad. Might be worth the money.

[436'd skylark]

its a two wire plug at the actuator. ones a ground, the other is power. pull it in 4x4 with the key on, and you should have power there.

There is a TSB about these actuators. when working properly they take about 10 seconds to engage. lots of complaints back in the day. GM makes a motor and an adapter harness that goes for like 230 out the door. It engages the 4x4 insantly like an old setup. far superior to the thermal actuator. if you do alot with your 4x4, you might want to consider it.

[shadygrady]

BUt I am curious, does this have manual locking hubs or actual auto locking?

It has the auto locking hubs,and I agree 150 isnt too bad to get my four wheel drive working.I found something at advanced auto fir 79.95 called a 4x4 actuator but they didnt have it in stock and the computer had no picture so I`m not sure if it`s the part I`m looking for.Gonna check out my actuator and make sure thats what it is before I order anything.Thanks for your replies guys.I`ve been searching some threads and it appears these things were a problem,may check out the one skylarks talking bout.I dont use it all the time but its my work truck so when I need it,I need it to work.

[keithr0005005]

i will almost guarentee your actuater is bad they are notorious for taking dumps. go to advance and tell them you need a 4wd actuater for your truck. installation is very easy. just unplug the wiring harness then with a big adjustable wrench or even channel locks undo the old actuater and install the new one. 5 minute job.

[stumpuller454]

yup sounds like actuator, if you don`t get 12volts to it check the ball switch on top of the t-case next, sometimes there contacts fail inside,...

[shadygrady]

unplugged and removed the actuator.It`s visualy ok but I put the voltmeter on the wires going to it and Its not getting 12 volts so `i`ll get another.Thanks

[stumpuller454]

Originally Posted by shadygrady

unplugged and removed the actuator.It`s visualy ok but I put the voltmeter on the wires going to it and Its not getting 12 volts so `i`ll get another.Thanks

so there isn`t 12 volts at actuator? this is a problem, there should be 12 volts key on and shifted into 4wd position, you`ll want to next check the ball switch on top of t-case, i think its a 1"1/8th or 1 1/16th wrench to remove it, pull it out plug it back in and cycle it "push ball in" wait 10-20 seconds to see if actuator moves, if it doesn`t check wires there for power, do that and work from there, unless you meant you had power all along, and i just typed a big storie(:! oh,!sometimes you can push the ball in really far to make the actuator work, this means you need a new switch. should work with about an 1/8 inch movement, you can kinda feel the sitch working inside when you push it, bla bla bla anyways let us know(:!