About a year ago I had the vacuum actuators, worked on and/ or replaced. about 5 months ago I notced the hubs trying to lock again while moving down the road. Instead of taking it right back to the dealer, I let the warantee lapse. Now, I'm on the forums noticing that there are supposed to be two solenoids on the firewall. I see only one, and a spot for a second. There are no disconnected wiring harnesses that I can see. Just a spot for a second solenoid. I don't know if the dealer messed up or what. As far as I know I have 4wd when the switch is turned. I am tryin to avoid having the dealer charge me another $800 for repairs that don't repair the problem again.