Where is the vacuum pump located on 1999 dodge diesel?

On a 1999 Dodge diesel (likely a Cummins-powered Ram), the vacuum pump is usually integrated into the front of the cylinder head, driven by the camshaft. It's not a separate, standalone unit like in some vehicles. You'll find it near the top of the engine, on the driver's side (from the perspective of sitting in the truck).

However, it's crucial to note that some later-model Dodge trucks, even within the 1999 model year, might have variations. To be absolutely certain, consult your vehicle's repair manual or a detailed diagram. A visual inspection, looking for a small, often cylindrical pump on the front of the cylinder head, is also helpful once you've located the engine's front.