Have an issue with my 4wd not engaging at random. I will start the truck in the morning and press the button and it goes into 4wd no issue. Then I will get to work and occasionally will need 4 wheel depending where I'm working, and sometimes it won't engage at all. Says service 4wd with the light on the 4 wheel button flashing. When I start my truck again after a few hours most of the time it goes right into 4 wheel when I try it. Bad ground or connection? Only seems to happen when the truck is running for a while. I'm not sure where to start with it. Truck is a 07 classic 1500

 

Well these fourms are just about as useless as my 4wd and 4l60.