not sure i understand the first question, you ask if your engine is too clean???
second one, well you migh have a pin hole in the CV boot as this seems like CV grease. Clean it and you might see the hole or see if it comes back.
third one, you have a small oil leak somewhere, could be from a...
yeah your transfer case is shot, either the inside is all chewed up or the splines of the differential in the transmission are gone. Do a search in this forum there is a lot of threads about this.
If it was the connetor on the rear diff, the 4wd light would always be on. The flashing light is...
i suppose you checked that the child safety switch in the driver door is not actuated? It could be the main switch also after looking at the diagram, you would need to see if you get some 12V at the rear switch but it depends how electrically inclined you are. If you can find both front and rear...
doubt it, i would need to see it but at this point, this is really trying to open something that is not meant to be opened unfortunatly. Otherwise you can order a new button and hope this is the problem
yes the wheels will still make the diff turn. it will be exactly like when the car drives in 2wd and doesn't need the extra traction from the rear and is not coupled with the main driveshaft
here is what it looks like without the transfer case. You can see the transfer case doesn't seal anything with the transmission. Rear diff will support itself but you need to remove the driving shaft from the car obviously. It really is a no brainer modification, you'll see it when you take it...
by taking out the door card and seeing if voltage goes to it? Does it work with the button on the door itself? It can be motor or switch, can't be much else
Usually yes, the voltage should lower to 12,7 if the alternator stops working. Weird issue, i suppose it has to do with what reads the voltage but no idea what it is
5J is a signal from the BCM(with car navigation) to the audio unit, pin 1M red/yel. I suppose it turns on the back up camera. It is only a signal between the BCM and the audio unit.