My A/C has a leak or disconnected hose. Does anyone know where I can get a diagram of the lines to inspect myself?

This may help you. No sooner had I finished writing this new piece, and your related question appeared.

Vacuum Hose Leaks

Heat and ozone cause hoses to deteriorate and leak, over time. Once a vacuum hose is disturbed, particularly on older vehicles, it's prone to leak. This is particularly true on air conditioner vacuum hoses, which control diaphrams going to blender doors, where even small leaks can be disastrous.

Here's a possible solution to air vents not working properly. Separate the vacuum lines and carefully service the connections with silicone grease. This will help to recondition and restore the seal. Obviously, you must use common sense and not apply too much and plug openings.

An excellent product to use in this situation is Motorcraft Silicone Brake Caliper Grease and Dielectric Compound (XG-3-A). It's available at your local Ford or Lincoln/Mercury dealer. It's amazing the number of other applications this product can be used for; e.g. lubricating O-rings, rubber gaskets, disk brake caliper pins, radiator and heater hoses, plus using it as a dielectric compound for weatherizing battery and starter terminals and cables, main grounds, main ECM ground, ECM connectors, coils, spark plug connections, coating spark plug porcelein, and tail and brake lights. This product also helps prevent wet starting problems in seemingly small, but significant, ways. I mention these other applications, so you won't feel like you are spending money on a product with limited use. Attention to detail makes a big difference when dealing with vacuum hoses. Frequently, it's the difference between a system working or not working.

A/C vacuum lines normally run along the firewall, from the power brake booster to the passenger side of the car. One main hose from the booster may separate into two hoses going to the inside of the vehicle. These are the connections I would focus on.