Where can i find schematics for the 98 4x4 system.

I know its electrical...my 4wd switch does not make that clicking sound or anything...its not even TRYING to engage. My interior lights are not coming on....if you have any ideas on this issue, please advise. Thanks

 

by interior lights, i mean the 4x4 and LOW RANGE lights in my dash are not coming on. thanks

 

Called the dealer. He suggests crawling underneath and lightly banging on the motor that moves you into 4 wheel drive. Sometimes these stick or get a bad spot on them. I tapped on in it and then I did hear a clunk when I turned the ****.

My light was coming on, but no 4x4. So, I read through this forum and found that the vaccuum lines running to the center-disconnect have issues. So I popped the hood and sure enough, the lines had dried out and were useless. I replaced (rigged) them with normal, rubber vaccuum line and it sort of works. I plan on replacing it with the correct part when I get a chance.

I still think I'm having a problem because the center disconnect does not fully engage unless I rock the truck a bit, makes a grinding noise. The vaccum solenoid that disengages the center disconnect may be stuck or have dirt in it, since the line that actually disconnects the center disconnect always seems to have vaccuum.

This crap always happens only when I need the truck....

 

I did that, i tapped my motor on the transfer case hoping for a remote sound...i did feel like it was trying, it was vibrating. My vacuum selenoids seem to be ok. Now, next to the front differential, their is a disk that holds those 2 vacuum lines, what is that?? I know its a diaphram of some sort...is that the thing that physically engages?

 

From what I observed yesterday, that diapham connects/disconnects the front driveshaft to the axles/differential. I pulled the boot and got someone to turn the button and I could see the diaphram working back and forth once everything was rigged.

You can also pull the vaccuum lines with the engine running and see if either has vaccuum. On mine, the blue line was broken somewhere between the dif and the connection farther up in the engine compartment.

 

on mine, the red one had vacuum...the other did not....are both lines supposed to have vaccum? Also...the movement that you observed...was it...change position permanently...or did it slide in/out and when back to original position? thanks doug, you are really helping out here.

 

On mine, the red one had vaccuum all the time and the blue would get vaccuum when I tried to put it into 4 wheel drive. When you turned it back to 2 wheel drive, the blue vaccuum would stop. I think the diapham is spring loaded to the center, so that when there is no vaccuum, it is out of 4 x4, but the red one keeps it out.

When I did it, before the fix, I put the red line where the blue one had been and put it into 2 wheel drive. I could see the diaphram move and then turned the driveshaft by hand and it turned the front wheels.

The diaphram stayed in place, wherever it was so long as vaccuum was applied to it on either side.

It's in a fun place to get to, huh?