Skip to main content ↑ ↓
Topic: Engine cooling fans (Read 759 times) previous topic - next topic

Engine cooling fans

Good morning everyone,

We have owned our coach over 2 years and have driven 20,000 miles. During that time I never heard the cooling fans come on or shut off until recently.

The fans are coming on within the first few minutes after start up and temps are still very low, under 100. They will run for a few minutes then turn off but will start up again a few minutes later again while temps are low.

I have read that there are several speeds for the fans and when they are turning on it seems pretty loud.

What should I be looking at or for and where?
We will be back at the coach this week and will time the on / off cycles from start up.

Thanks



Re: Engine cooling fans

Reply #1 –
Quote from: Lt403 –
What should I be looking at or for and where?
Check the oil level in the hydraulic pump reservoir?

I can't hear the sound of our fans running over the engine noise, but you should be able to check for fan operation by simply holding your hand (or a sheet of copy paper) in front of the radiator grill.  You should feel the air being sucked into the grill when the fans are running.

There are many discussions on the Forum about electronic and hydraulic fan controllers.  The Forum SEARCH tool is your friend!

Here are a couple to get you stated:

Hydraulic fan controller

Hydraulic fan controller DIY

Source Engineering Inc | Custom RV Chassis | Eugene, OR


Re: Engine cooling fans

Reply #2 –
Sounds  like the electronic control box is failing. The pumps are a variable speed and are controlled by oil pressure resistance in the control circuit. More resistance more pressure. Higher fan speed. No pressure/resistance no speed. My was the same and after reviewing i opted out and went to a manual setup. Currently happy with my setup but still have a couple tweaks to make
Scott

Re: Engine cooling fans

Reply #3 –
thanks Chuck,
I had been reading but always like to double check to make sure what i need will fix the problem.
It seems like everyone is "upgrading" to the mechanical wax ring. don't think i will go that route since i cannot do it myself. will probably remove and replace what is on there after i take a look for anything obvious. FOT gave me a an estimate for the part for $1100. and they won't have it till Feb of '22.
I think the part # is P23458  1090273  electronic fan control.

Scott, your post is one of the ones i read. Great to be able to do it yourself, customize it, and have that background and equipment. sorry to say i don't., and i don't know anyone that can do the work that i trust.

i'm looking around online to see if i can find the part somewhere.

Re: Engine cooling fans

Reply #4 –
Quote from: Lt403 –
thanks Chuck,
I had been reading but always like to double check to make sure what i need will fix the problem.
It seems like everyone is "upgrading" to the mechanical wax ring. don't think i will go that route since i cannot do it myself. will probably remove and replace what is on there after i take a look for anything obvious. FOT gave me a an estimate for the part for $1100. and they won't have it till Feb of '22.
I think the part # is P23458  1090273  electronic fan control.

Scott, your post is one of the ones i read. Great to be able to do it yourself, customize it, and have that background and equipment. sorry to say i don't., and i don't know anyone that can do the work that i trust.

i'm looking around online to see if i can find the part somewhere.



Being fairly new to this world, I'm also not yet as confident or mechanically inclined as many here.    However, I bought the mechanical conversion kit from Source engineering and had Keith Risch at MOT install it.  (In our case the fans were always running at 100%)  MOT had a 3rd party do the weld on the coolant pipe, but got that done quickly.  Cost of the part and the install was that replacing the electronic control. 

From what I gather, the mechanical wax valves are more reliable than the electronic controller.  Also, in  our case, there was a long lead time in getting a replacement.  Keith said the old controller could probably be rebuilt, but for me it was more expedient to just replace it with the wax valve conversion.



Re: Engine cooling fans

Reply #5 –
I've been looking for the part and according to the manufacturer it's proprietary to Foretravel.
When we're back at the coach this week I will look for the obvious and if I can't fix it I'll get the mechanical wax valve.
I guess if MOT does so will FOT.
Thanks
 

Re: Engine cooling fans

Reply #6 –
Did some investigating yesterday and found the hydraulic fan controller sitting on the rear cross member, lower right side of engine. I thought it was going to be under the fans somewhere.

Disconnected the plug and saw a good amount of  grime on both sides of the plug.
Used CRC electronic contact cleaner and got it all out., let dry and reconnected.

When we started the coach, the fans did not turn on high like they were before. Engine sounded like it did prior to this issue. Idled for about 10 minutes without fans going on high.

Ran 400 miles yesterday with engine temp at 179, trans temp 186. Average speed 72 mph.
800 miles to go to destination.