So I finally got to work on my 4x4 system tonight and found some good and confusing news...

First off, i thought there was either a vacuum leak or the actuator on the axle was dead.

Well we started off trying to find a vacuum leak, we took the 2 lines off the vac resevoir and they both had vacuum, so then we traced it to the solenoids on the firewall and they weren't allowing vacuum.

So we took a hose and ran it from a line off the vac resevoir and to each hole on the solenoid and it would engage/disengage the actuator...

So that rules the actuator out as being a problem.

Next we worked on the solenoids, they won't work on their own, so my uncle checked for power to the solenoids and it didnt check out, so he ran a direct power source to them and voila! The actuator worked via the solenoids.

Now that rules them out. The only other thing i could remember to check was the switch on the transfer case. So we tested for power and one wire was 12 volts and the other was like 4 or 5 volts. So we took it out and cleaned it and this and that.

Thats where we are at at this. The switch will turn the LOW RANGE light on but will not make the 4x4 light come on.....

Is the switch my culprit here? I can't think of anything else that could be wrong. Everything else checks out, and i want to, if possible buy the switch tomorrow.

Thanks and sorry for the long post.

 

You forget there is a GEM module that controls the 4X4?
The dash switch only request the action by signaling the GEM.
The lamp comes on after the action is complete.
The Gem lights the dash lamps.
Be sure the transfer case motor moves to it's first position after you operate the switch then the vacuum actuator is allowed to pass vacuum through the fire wall relay.
For 4 low, the truck needs to be in neutral with your foot on the brake to advance past 4H. The transfer case motor must move to the next position.
The case motor sets up the trans gear chain for 4H and tranfers it for 4L and alters the PCM program for shifting.
What's hapening?
Don't order parts until you get a lead on what the cause it.
No use guessing because it cost more money.
Good luck.

 

I forgot to note i have the manual shifter on the floor if that makes a difference.

 

Thanks for the response bluegrass appreciate it!

Basically whats happening is whatever tells the solenoids on the firewall to release vacuum is not working. Because we tested the actuator and the solenoids and they both work....

So I'm at a loss here on what is going wrong.

 

I was just reading about the GEM and problems that can occur, and I havn't really experienced any weird problems except a couple.

My cruise hasn't worked in a while but for some reason today it was working, maybe my uncle messed with something that fixed it...

A few months ago my whipers completely went out and would not work but soon came on and havnt had the problem since, other then that thought i havnt had any electrical problems...

It's an XL 5 spd so no power windows/seats/ etc.

 

I fixed it! It was a damn fuse...go figure, thanks for making me not buy that sensor bluegrass !

 

Good enough.
Sometimes my replies are 'leading' and somtimes 'kert'.
They are designed to get people to think a little deeper and be able to help themselves.
Happly holidays to you and your family.

 

Yes but it's meant well and in good terms. I was thinking all day about whether or not to buy that switch on the transfer case, and i had gotten a bonus from work, so i almost went to the dealership

But i remembered what you said about the GEM so i can home to look it up and decided to check the fuses.

Gave me more money to spend on my son for xmas

 

If you haven't gotten the cruise recall done, you better go do it. It's a fire hazard.