I had the dash tipped up and was checking fuses after my debacle with the batteries (different post) and noticed-over to the left-- an electrical schematic or spellout for what size fuses and what they are for. The 15 amp--far left rear-- is for a drier. So, what is the drier for and what does it do? 1989 GV ORED with the old DD8.2 Turbo.
Dryers are just downstream of the engine driven air compressor. They remove moisture and oil from the air before it goes to the storage tanks and on to the the air suspension/air brakes.
The 12 VDC is for a heater that keeps the water from freezing in below freezing temperatures.
Brett
Nitehawk, Here is a view of Haldex Dryers, yours may be a different Brand or Model.
FWIW, I screwed up and did not service mine when I should have and ended up doing a full rebuild. Found a broken plastic part so it would have failed anyway. This component is easily overlooked during service, changing the two filters is not a tough job depending on where it is located and will save a lot of grief later.
Gary B