The method of controlling vacuum operated locks started with a single-position pull switch then changed to a two-position pull switch and eventually to a rotary knob at the start of the 1985 model year (VIN 85 F 900 001), but all methods had the same layout of vacuum pipes under the bonnet. This diagram is a schematic of the setup on vacuum lock vehicles.
Items in green are only fitted to vehicles with air-conditioning
To make things simple for the Monkey Lads™, Audi colour-coded some of the hoses. You'll be lucky to find any trace of this now because the dye will have faded over the years and replacement hoses had no coding.
Colour codes will be listed at a later date
Pipe schematics for the three types of switch are detailed here.
{© IJH 2001}