Engine overheating

Dave.....Save yourself some money. Your Monaco product stacks the Charge air cooler on top of the radiator. Most other brands sandwich them together. On yours, as Brett said, draws air like a large vacumn and pushes it through the CAC and radiator and out the back. Monaco uses a large metal shroud that seals against the radiator at the bottom. The shroud is square and mates up to the edges of the radiator and then tapers toward the engine and into a round opening. If you look closely through the fan blades with a flashlight, you'll see debris in the very bottom corners of the shroud where it meets the fan. I clean mine every year and find newspaper, leaves, etc. I use one of those long pinchers that you push the button on one end and three fingers pop out on the other end to remove the debris.

Once you've done that, take a garden sprayer and fill with a mixture of Dawn dish soap or Simple Green. Use the wand to spray around the entire shroud area from the closet opening. Close the opening and spray some more from underneath. The sprayer makes it so you don't have to crawl underneath. Let it set for a few minutes and spray from underneath with a garden hose/spray nozzle. Once I see the water runoff turn clean, I start the engine and then spray with more water, allowing the fan blade to push the water through. The rear of the radiator can be quickly rinsed, but will be pretty clean since the Monaco's are stacked atop each other.

This sounds like a long process, but really only takes a few minutes. If you're not absolutely sure the radiator is clean, you'll be wasting your money having any other diagnostic work done.