Install a Concours '65-'66 A/C System

As stated earlier, the compressor was already mounted on our engine, so Doug only had to install the service valves onto the compressor. On the upper valve, the hose end faces toward the firewall, and on the lower valve the hose end faces toward the core support.

With any connection on the A/C system, be sure the seal is oiled and use two wrenches when tightening the connections.

Two 11/4-inch holes have to be drilled in the core support for the liquid line and discharge hose. The locations for the holes are in the original core supports by the stamped dimple in the metal. Use the line to measure where the hole has to be cut. This is the lower hole; the liquid line 90-degree fitting has been installed through the opening. Don't forget the rubber grommet for the hole.

The discharge hose comes off the condenser and passes through the core support to the compressor. Use the dimple or hose to locate the hole that has to be cut.

The modified discharge hose is attached to the service valve on the compressor and tightened.

The suction and liquid line hoses are attached to the rear of the underdash evaporator unit in preparation for installing the underdash assembly. These hoses will be routed through the firewall. Look for an oval knockout plate on the firewall that has to be removed to allow the hoses to pass through.

After carefully sliding the underdash assembly roughly into place, the liquid and suction lines are routed under the hood. The suction line attaches to the upper service valve on the compressor, while the liquid line is attached to the aluminum section of the two-part liquid line.

The liquid line and its aluminum half are assembled and secured to the inner shock tower with the included rubber-covered clamp and tapping screw. There is a dimple mark on the shock tower where the tapping screw will be installed.

With all of the lines connected, the underdash assembly can be attached to the dash. Mounting holes are already in place in most cars, but early cars might need the right-side hole drilled out beneath the glovebox.

This is the firewall opening mentioned earlier. Once the hoses are routed through, pop the rubber grommet in place over the hoses and secure the whole thing with the included grommet retaining bracket and two tapping screws. The wire passing through the center is the clutch engagement wire, which is routed over the engine to the A/C compressor clutch.

We couldn't watch as Doug drilled the drain-hose hole through our brand new floorpans, but it's a necessary evil of the installation. The carpet is carefully trimmed to prevent pulling by the drill bit, then a hole saw is used to make the opening.

For V-8 applications, a new fan shroud and a high-flow, six-blade cooling fan is installed to keep the engine cool while the A/C is keeping you cool.

To ensure proper belt tension, Classic Auto Air installers use this handy belt tension gauge. The Mustang A/C system is definitely known for its belt slap, which is more pronounced with a loose belt.

With the system installation complete, all that's left is to charge the system, check for leaks, and reinstall the front-end items. We can quickly charge the system and check for leaks at Classic Auto Air before reinstalling the front valance; but if you're following along at home in your driveway, put everything back together before going to the A/C shop for system charging.

After charging the system, Doug closed up the windows, placed the system on the coldest setting, and checked again for leaks and any other problems (there were none). Once the system temperature stabilized, we were pleasantly surprised to see Doug's digital thermometer (whose thermocouple was positioned in the center vents) read a chilly 38 degrees. We shouldn't have any problem staving off the Florida summer heat when we show or cruise, and the system looks like it came down the assembly line like the rest of the car.