How To Install A Coleman RV AC Rooftop Air Conditioner

Coleman RV air conditioning units are perhaps the most well known of RV ACs in the world of RV users, whether they be motor homes, camper travel trailers, or pop-up campers. Along with other fine camping products, the Coleman rooftop AC units are considered one of the most efficient and reliable brands made.

Installing or replacing a new AC unit is something even the most hands-off type of person can accomplish with a little study and work. This article is intended to walk you through the steps of installing a new Coleman AC in a camping unit, or replacing an old unit, no matter the make or model.

If your new AC is a replacement model, it will be necessary to determine which model to use in your travel trailer or motorhome. Coleman rooftop AC’s are available in two models. The 13,500 BTU (British Thermal Units) model is perhaps the most purchased of the two models offered.

It is often used in applications where two units are used to cool a large motorhome or camper trailer. Working independently from each other, these 13,500 BTU units can be used singly or together for efficient cooling, depending on how hot the weather is.

For those middle sized camper trailers or motorhomes there is the Coleman Mach 15 air conditioner. This fine unit fits the niche perfectly with enough cooling power to keep you cool on the hottest summer days. Installing one of the Mach 15 AC units is no more difficult than the 13,500 BTU model.

Check your old rooftop unit to determine the correct size if you have any doubts as to which Coleman unit to purchase. Both of these air conditioners may be found at very reasonable prices on this page.

Buy the best model for your particular camping unit. If ordered from this page, the AC unit you chose should arrive at your location in just a few days. In the meantime you can remove the old RV AC unit and prepare for the new one.

The first step in removing the old unit is to detach the ceiling assembly from the unit by removing the screw holding it to the ceiling. There are normally only four screw which need to be removed but some older AC units may have more or less. Hold the AC ceiling assembly up with one hand while removing the screws to prevent the assembly from falling abruptly.

It may be necessary to unplug the wires leading from the AC ceiling assembly to the rooftop unit before it is completely free. It is helpful to have someone assist you in this step for ease of removal, but the assembly can be allowed to hang from the wiring while they are disconnected. Remove the cover from the electrical junction box and disconnect the electrical line wires.

Note the wire colors and the ground connection in the old junction box as the new Coleman RV AC will use the same configuration when it is time to reconnect the electrical line to the new unit. After this step is complete, remove the long bolts from the ceiling bracket. These bolts go up through the roof and into the rooftop AC unit itself.

Detach the vent which connects the ceiling assembly to the rooftop unit. Some vents are made of thin aluminum and some use a flexible vinyl tube to make the connection. Both use screws to hold them in place. At this point you will need to gain access to the roof of the motorhome or camper trailer.

The photos used to illustrate the steps necessary to install your new Coleman AC unit are of a 1986 Airstream Sovereign travel trailer. The old Coleman Mach had seen its better days and had given many years of dependable service. It still cooled fine but the fan motor sleeves had worn to the point of needing a nudge to get it going.

Since this AC fan motor had sleeves instead of standard bearings, the shaft itself was worn prohibiting a rebuild because of the expense. Instead of only having the bearings replaced, it would be necessary to replace the shaft along with the winding mounted on the shaft. A new motor would perhaps be cheaper to install.

Besides the fan motor problem, the RV AC shroud had begun to develop cracks at the stress points around the four retaining bolts and in some of the air vent louvers. Replacing the old shroud isn’t cheap either. So, all things considered, purchasing a new Coleman 13,500 BTU air conditioner was the best option.

If the AC compressor in the old Coleman AC went on the blink, which was entirely possible, the owner could have more than paid for the new Coleman unit by the time a new AC compressor was purchased and installed. The combined cost of the new AC fan motor, shroud, and compressor was just not acceptable when a new unit would solve the problem and perform more efficiently.

Care should be taken when removing the old rooftop AC unit to prevent any damage to the motorhome or camper trailer roof.

For installation of the new Coleman AC unit into the Airstream travel trailer, we used thick padding to protect the surface where the ladder was used and on the roof itself.

Motorhome roofs are normally rubberized so the chance of damaging them are less than on a metal roofed RV.With the electrical wiring, the retaining bolts, and the ducting unfastened, the old unit is ready to remove.

It may be necessary to carefully slide a thin putty knife between the bottom of the old AC unit and the roof surface as any previously applied roof sealants will have caused the old AC unit to be adhered to the roof.

When the old AC unit is removed, carefully lower it to the ground. Clean the area around the vent hole carefully being sure no rough spots or adhesives remain to interfere with the new seal.

Remove the shroud from the new Coleman AC before transporting it to the roof of your camper. Check for any shipping blocks or other objects which may interfere with the moving parts of your new AC.

Once you have centered the new unit over the duct hole you may attach the retaining bolts and bracket. Tighten the bolts gradually moving from one to the others until the seal is uniformly tight against the roof.

Do not over tighten these bolts. They just need to be snug enough to keep water from seeping beneath the gasket and you can always tighten them further to stop any leaks if needed.

Replace the shroud using the retaining nuts and being sure the shroud is securely fastened to the unit. You are finished with the rooftop part of installing the new AC unit.

Follow the instructions provided with the new Coleman unit to attach the flexible duct in place.

If you purchased the optional heating element now is the time to attach it to the ceiling assembly. Reattach the electrical line wiring to the wiring in the unit junction box.

Using the provided screws, attach the ceiling assembly in place and re connect the power source to the motorhome or camper trailer.

Test run the new AC unit to check for any malfunctioning parts or a lack of cooling or heating if the heating option comes into play.

Your new Coleman rooftop RV air conditioner will give you many years of trouble free service if maintained properly.