How to Install a Roof-Top AC Airstream

Removing the Old AC Unit

• 1

  Turn off the power supply to the Airstream trailer. You may need to turn off the circuit breaker, unplug the trailer from the electric hook-ups or shut off the generator, depending on how electricity is supplied to the unit.

• 2

  Free any trailer components that prevent access to the old air-conditioning unit. This might require removing doors or curtain rods, depending on the Airstream trailer model. Use a ratchet wrench or screwdriver for loosening bolts or screws to remove these components.

• 3

  Slide a screwdriver under the control knobs and pop them off the unit, though you may be able to pull them off without a screwdriver. Remove the screws that hold the air-conditioning shroud in place. There are usually two to four screws that hold the cover against the ceiling.

• 4

  Pull the air conditioning shroud away from the ceiling. Depending on the air conditioning unit, it may simply release when all the screws are removed or you may need to push in tabs to release it.

• 5

  Test the power supply with a multimeter to ensure that no power is circulating, which could cause serious injury. Set the meter to 120 AC volts and so it reads ohms. Connect the test probes to the power switch. A reading of "0.L" or infinity indicates that the power supply is turned off.

• 6

  Pull the wiring harness out from the junction box and allow it to hang, allowing you to remove the rest of the shroud.

• 7

  Disconnect the mounting bolts from the metal mounting chassis. When the plastic cover is removed, a metal piece of the shroud is revealed. Use a ratchet wrench to loosen the bolts and free the chassis.

• 8

  Cut the electrical supply line with wire cutters close to the point where the wire connects with the metal shroud. This leaves a long length of wire for the new air conditioner.

• 9

  Pry the roof-top unit off of the roof and remove it. Thick layers of adhesive may need to be cut away with a razor knife in order to remove the unit, while others may simply pop out of place.

• 10

  Clean the mounting surface around the roof top opening using an adhesive removal product and a putty knife. This ensures a better fit and smoother installation of the new unit.

Installing the New AC Unit

• 11

  Center the roof-top AC unit over the opening in the roof. Distribute the weight evenly over the braces on the roof to prevent cave-ins.

• 12

  Set the air-conditioning duct in place. Line it up with the duct on the AC unit and tighten with the provided screws.

• 13

  Position the metal mounting chassis onto the ceiling. Mount it with the provided bolts and a ratchet wrench. These bolts secure the unit to the roof.

• 14

  Plug the multi-pin connector into the multi-pin outlet on the air-conditioning unit. The connector is a cord with several round prongs that match up with the round female ends of the outlet.

• 15

  Insert the electrical supply line through the hole in the back of the connection box. Pull at least 6 inches of wire through the hole. This is the black wire that you cut earlier in order to remove the shroud.

• 16

  Cut the black sheath from the wire and pull it back to reveal the smaller wires inside. Strip the colored casing from each wire to expose the internal metal wires, which are usually copper.

• 17

  Connect each wire to the corresponding colored wire on the air conditioner's connection box. Twist the wires together a few times and then cover the connection with a wire nut or cap. Wrap each wire with electrical tape on either side of each wire nut.

• 18

  Push the wires up into the connection box. Tighten the clamp that holds the supply line in the box and install the cover with the provided screws.

• 19

  Position the plastic air-conditioning shroud on the ceiling. Line the holes for the controls up with each of the metal control studs. Install all the necessary screws to secure the shroud to the metal chassis.

• 20

  Pop the air filter grates into place on the shroud. Pop the control knobs on the metal control studs. Turn on the power supply to test the air conditioner.