1988 XT6 5 speed manual

 

4WD works fine but the center diff lock button won't engage it. I currently swap vacuum hoses to engage the diff lock.

 

I've already swapped buttons.

 

Here's what I think will tell the issue to someone crafty - when I give the vacuum hose to the 4WD mechanism direct vacuum, the differential locks just fine perfectly like normal.

 

Then - if I press the button, the center diff lock light will light up - so the circuit is all there and working.

 

And then if I remove vacuum the diff lock STAYS LOCKED (light on and all) until I depress the button. So the circuits and all work.

 

I think a person more adept than me at electronics would probably know exactly what this is.

 

Probably a solenoid?

Sounds like the vacuum solenoid that activates the diff lock died -- so even though it's getting a 12 volt signal, it's not letting the vacuum through to activate the diff lock. The other solenoid that deactivates the diff lock is still working, which is why the button still works to deactivate it. This is essentially what just happened to the pushbutton 4wd on my justy -- it will still go into 4wd, but to get out of 4wd, you have to swap the vacuum hoses under the hood. When I tested the two solenoids, the one that should send vacuum to the 2wd vacuum hose doesn't do anything when it gets power.

 

Z

oh okay, great i'll just swap that out.