2005 FX4

I've read a ton of posts on this issue, but I have a couple questions I'm hoping someone can answer.

I got in some mud a couple weeks ago, flipped my 4x4 switch, and nothing. Had to walk for help.

Anyway, after troubleshooting today with the help of the internet, I think I have it narrowed down to the vacuum solenoid, or the wiring that controls it.

But here's my question, nothing I've read has mentioned if the 4wd indicator light still works when the solenoid is bad. I'm getting no lights. Is this normal?

Secondly, does anyone know if I can check voltages at the vacuum solenoid pigtail to determine anything? I seem to be getting power to one wire no matter where my switch is 2wd, 4hi, or 4lo. This makes me wonder about the switch or the wiring.

​​​​​​I'm an electrical moron, so I'm not sure what I should be seeing.

 

You should be able to unplug the vacuum hose at the solenoid and the 4WD should engage. The solenoid keeps it from engaging and when it starts to go bad the 4WD slightly engages and makes a terrible clicking sound. I don't remember if the indicator light was going on when my solenoid went bad.

 

Yeah, 4wd engages if I disconnect the vacuum. But, if the solenoid is plugged into the pigtail, there's constant vaccum through it, no matter where the switch is set. If I leave the hoses connected, but disconnect the pigtail, vacuum is shut off (4wd engages). So, the solenoid is capable of working, whether it is or not. I'm wondering if it's not getting a signal to work.

 

I'd just replace the solenoid and see what happens.

 

You might also have an issue with your 4WD actuator motor, you can test this by seeing if your front axles spin while rolling when your switch is set to 4H.

 

Sounds like your solenoid is good. Just for the heck of it check fuses 11, 29, 30 & 111.

 

Oh, yeah, I forgot to mention in my first post, 29 & 30 were blown. That's one reason I suspected there might be some sort of wiring issue. Replacing the fuses didn't fix it, but they haven't blown again.