you can find it in a workshop manual
on the sticker under the hood
You can find a vacuum hose routing diagram for a 1988 Mercedes 190e 2.3 in the owner's manual. You can also find it at various auto part stores.
Haynes Repair Manual for Volvo 760/740 has diagrams of the vacuum sub-systems.e,g. the EGR, the ignition etc
You can find a vacuum diagram for a 1988 Silverado with a 5.7 engine at your local auto parts store. You can also find one at most major book stores in a Silverado repair book.
It is a vacuum line diagram for a 1988 Toyota Corolla. What else would it be. :-) Just playing. You can find one [http://www.themotorbookstore.com/corolla2.html Here]
When making any changes to a vehicle, a diagram can help point the person in the right direction. A vacuum line diagram for a 1988 Plymouth Horizon can be found in its maintenance manual.
One can find a wiring diagram for a Volvo 245 at Turbo Bricks. These can also be found at Volvo Club and at Volvo Tips.
The Chiltons/Haynes 72300 has the vacuum circuits divided into the emissions, Fuel and brakes sections of their manual covering each vacuum hose.
A vacuum hose routing diagram for a 1988 E 150 van can be found in the vans service manual. The manual can be bought at most auto parts.
Which vacuum diagram The Underhood for the engine or the vacuum for the interior /AC system?
You can find a free Ford F1 50 vacuum diagram at most Ford dealerships. Many auto-parts stores will have the vacuum diagram.