4-wheel drive not 4 wheel driving

[Eric Wettschreck]

I have an 89 chev 1/2 ton pickup.

I'm no stranger to turning a wrench, what I am a stranger to is this type of shifter. I'm used to to the older style Chev shifters that have a linkage direct to the transfer case. The shifter on this truck has the same look, in the cab, but I'm told there are electronic magnetic solenoid thingys that actually engage the transfer case.

I've been told my problem is most likely in the shifter magnetic thingys. In the past when I shifted it into 4 high I had to wait about a minute for it to actually engage. I was told it's because the electronic magnetic solenoid thingys were weak.

My questions are, what is the real name of the electronic magnetic solenoid thingys and how do I test them to make sure this is really the problem?

One minute it worked, the next time I put it in 4 high it didn't and hasn't since.

[Macgyver55]

Probably the actuator on the front differential is bad. The transfer case engages manually with the lever but the front differential has an electronic actuator. An 89 would be the "old style" which did have some issues but there is an updated one that also includes a harness update. Changing the part itself takes only minutes. (it simply unscrews) The harness will take a little longer to locate the correct wire and solder and heat shrink. Shouldn't be too difficult for you.

[Eric Wettschreck]

Thanks a ton!!!

So......The actuator is threaded into the front differential?

[Macgyver55]

Yes sir, should look like this.....

[Jeremy airjer W]

Actuators are fairly common.

[Eric Wettschreck]

Thanks guys. Gotta love the FM tech info.

[Eric Wettschreck]

If I take this part out and put 12 volts on it, what should happen?

[Macgyver55]

I don't have one around to look at but I believe there is a rod or something that extends out when power is applied. The old ones (if I remember corectly) used a heating element that would heat up and expand something inside to force the rod out. The updated ones do not work the same way. (Assuming this is the problem) If you don't want to do the wiring update, you could check around and see if anyone still has the old style on hand and maybe even get it cheaper.

[Macgyver55]

Boilerguy, did you ever get this resolved?

[Eric Wettschreck]

Sorry, I've been away.

I really havn't done too much with this yet, and I don't have heat in the garage so I'm kinda waiting for the mercury to rise juuuuuuuuust a bit.

Thanks for askin. I'll let ya know what happens.

[Eric Wettschreck]

Macgyver and Airjer, Here's the scoop.

I checked for voltage going to the actuator, yup, it's getting power. Next I took it out and put voltage on it. Nuttin happening.

90 bucks later (not too bad) put a new one in and I got 4 wheel drive back!!! The parts store had one without the wiring harness upgrade, which is really fine with me. I figure this is far from a new pickup. If the old one lasted that long the new one will last as long as I need it to.

Thanks a ton you guys for your tech help. I'm not a stranger to turning wrenches, but I don't know that much about this particular end of things. Appreciate the help.

[Macgyver55]

Glad to hear it....happy to help.