Hello, I have an 03 SC that is having some problems with the 4wd. When I turn the **** to 4wd the light comes on in the gauge cluster, Sinetomes it engages , sometimes it doesn't. It also seems like when it does engage into 4wd it kicks out as soon as I get on it when I'm in the mud. I have replaced the solenoids and checked for vacuum leaks. I have the actuator but have not installed it. Any ideas would be helpful. Thanks in advance!

 

maybe the attached vacuum diagram will help here.