Show me where the low pressure valve is on a 1999 ford expedition?

The 1999 Ford Expedition doesn't have a single, easily identifiable "low pressure valve" in the way some systems might. The low-pressure side of the A/C system manages refrigerant flow primarily through the expansion valve (or orifice tube, depending on the specific system configuration). There isn't a valve you'd typically adjust or service directly.

To find the relevant components on your 1999 Ford Expedition, you'll need to look for these:

* Expansion Valve (most likely): This is the component that regulates the flow of refrigerant from the low-pressure side to the evaporator. It's usually located within the evaporator housing, which is behind the dashboard, making it difficult to access without removing parts of the dash. It's NOT a valve you typically adjust; replacement is the common solution if it fails.

* Receiver/Drier (low-pressure side): This component is part of the low-pressure side and contains a desiccant to absorb moisture. It's usually cylindrical and may have a fitting for service ports. You'll likely find this under the hood, possibly near the firewall. It's not a valve itself.

Accessing these components requires significant automotive experience and specialized tools. Working on the A/C system involves handling refrigerants which are dangerous if mishandled. It's highly recommended that you take your Expedition to a qualified automotive technician for any A/C service. Trying to find and work on these components yourself could lead to injury or further damage to your vehicle.