Anyone added an electric radiator fan?

A new rad isn't out of the question - I dd it on my old Monaco, changing from a 3 core to a 5 core which cured any overheating it would ever have - just don't have the time or tools to do it right now.

I put a small e fan on the trans cooler of my TV wired in with a fuse and simple dash switch. I throw it on when ever I cruise into a town or CG. Not sure if it really helps all that much but I don't think it hurts either. It certinly gives are flow where their was little before (in town, traffic back-up ect,). Total cost was around $40. I say go for it.

A better bet is a new radiator as they slowly lose the ability to move water with age. Yours is now nearly 20 years old if original. If you can get one with a bigger core, it will give you more margin. I have been unimpressed with aftermarket electric fans over the years. Many of them seem to run too fast and don't move much air.

Thanks for the input. When I did my research, I did see that good forward motion is more than sufficient to keep the engine cool and in fact, driving across the desert at 55mph she was right in the sweet spot.

The issue is that when we get to the rockies (think Vail Pass on the I70) we will be down to 10mph, foot planted in the floorboards, 1st gear and screaming - it's just the way it is for about 10 miles :(

So my thinking is that an e-fan will help the systems, not that they are not functional, just that a bit of extra help wouldn't hurt it - right?

There isn't much that I can do in cleaning up the airflow through the hood - we have the slant nosed model (see below) so additional scoops aren't really an option and at low speed wouldn't be very effective either

From the picture that you posted it looks like the one that I have. Here is my experiences with the electric fan. When I first bought the MH it overheated just looking at a hill. It actually melted the fan sensor at temp gauge sensors in the heads due to exhaust manifold leaks. After installing headers I hardwired the fan with a switch on the dash, thinking when I saw a hill coming I could start the fan at the bottom of the hill before a temp increase. From what I observed once the MH gets over 45 mph the fan has little affect on the eng temps. The fan helps at idle in hot weather with the AC on. The fan also helps to move air once you shut off the eng. The dash heater has more affect on reducing temps than the fan. Once the fan clutch kicks in you can very quickly see the temp gauge fall. So my conclusion is that it helps somewhat but if you are having overheating problems other things like headers, larger radiator( more rows larger dia tubes), new HD thermostat, air dams for front, free flowing exhaust etc would have a greater affect.

Your fan should work fine, protect it with a 15 amp fuse, remember the 10 amp draw at 13 volts is only 130 watts, or about 15% of one horsepower, while the engine fan is well over 1 HP, perhaps 2?

Fred.

Hi,

When you encounter a overheating RV, the first thing to think about is a new thermostat. If the old one is only opening about 40%, then it can cause overheating, and for about $15 can be replaced.

Second thing is spray on some simple green, then hose off with a garden hose. If the water it really dirty, it can be the source of your troubles, dirt build up can lessen the radiator's ability to get rid of heat by 5% to 15%. So a clean radiator can cool off about 5% cooler than a slightly dirty one, 15% better than if it was really clogged with dirt deep into the coils.

The main fan will move air about 1,500 - 2,000 CFM at the pressure drop through the radiator and condencer while at 2,000 RPM while the clutch is not engauged. WHen the air going out of the radiator across the water pump is over 150F, then the fan clutch should go into direct speed mode, or the same as the input RPM, a slight overdrive above the engine RPM. At this point, 2,000 engine RPM whould bring through around 6,000 CFM.

Also recall that the radiator has about 4 square feet, and at 60 MPH, the motorhome is moving forward at about 100 feet per second, or 5,300 feet per minute. So this is 5,300 X 4 square feet per minute, or about 21,200 CFM if there was not anything in the way to restrict the airflow, yet the radiator, condenser, and other things in the way help prevent that much air from going through the radiator.

Some say that a 3,000 CFM fan will restrict the air more than enhance it. Well if you are getting 21,200 CFM at natural flow, it might be true. Yet once parked, it would be REALLY handy to turn on that fan, and blow some air through the radiator, across the engine, and cool both quickly. I have found that on a 90F day, shutting off the engine, the floor will warm up a long way, so on the second day of camping, the floor is much cooler in my case. That fan will assist in cooling the RV a lot. While parking, or running less than 10 MPH, then the fan will enhance airflow. Yet at 60 MPH, the air going into the radiator will be more than adaquate to cool the radiator IF it is clean.

Also a thermostat that only opens 40% will cause overheating in a RV while climbing. No increase in airflow will reduce the engine temperature if the thermostat is not replaced.

I had a GMC motorhome with a 2 core undersized radiator. I ende up installing a very oversized transmission cooler, so that it cools all the transmission fluid, before going into the radiator, then to the factory cooler, then back to the transmission. Before modifications, I would run 235F trans temp all the time - even on flat ground on a 90F day, and afterwords, the radiator was slightly cooler, while the transmission was between 190 and 200 unless I was climbing a mountain, where it might reach 210 for a short time.

I know another RV.net member who changed to replace his radiator tank transmission cooler with three extra large heavy duty transmission to air coolers, only to find out that the factory thermostat was not opening all the way, and had to be replaced. This after removing the radiator, and cleaning it.

Fred.

I'm not familiar at all with your RV. Can you increase air flow by increasing the ventilation to the engine? I'm thinking car style hood louvers. I found a 96' picture of what might be your RV. Looks to have a swing up front door? Any non structure areas that you can cut? What about the back area the engine bay that vents elsewhere? The metal hood louvers can be painted to match.

Are looking to add the electric fan as a pusher? There has been some testing on light duty vehicles. The electric fan does draw less overall horsepower and moves less air than mechanical on average. Make sure mechanical fan shroud is installed correctly.

from what I have heard from racing circles, they don't move enough air to get the benefit you need to keep the motor from over heating

I put one in my Allegro Bay , mainly so I could keep it on when I shut the engine down . All that heat came into the house until then .