I've owned this coach for the last 4 years now. We take a yearly vacation to the same location in Colorado every summer. The first year there was no problem. Every year since, it seems to heat up easier and easier. I do have 4 miles of dirt road to travel every time I leave my house. But I wash the radiator out all the time. I replaced the thermostat and that didn't help. This year I noticed a sound and found the bearings on both fan hubs were dry and stiff. So was the idler pully and tensioner. I replaced all of that and now it spins freely. I figured that was slowing the fans down enough to cause the problem. But it didn't seem to help one bit. I noticed on a friends coach he has a full piece that covers from the bottom of the radiator all the way under the other coolers, i.e. intercooler, oil cooler, condenser. But mine is all open. I would think that only makes it not pull air through the other coolers as much but the radiator is still getting plenty of air? It's been that way since I bought it. My other thought is I know back when I first got it, when you turn the AC on it seemed to speed up the fans, even at a stand still. But it doesn't seem to do that anymore. Is there a sensor somewhere I need to check. It also has an electric fan mounted to the outer most cooler that doesn't seem to be working. Is that part of the same sensor? This is a dual fan setup driven from a single hydraulic motor. My only other thought is to pull the radiator and take it to a shop to be gone through. The coach only has about 60k on it.