Cummins ISB 340 Engine Overheating Overheat Fan Clutch Thermostat Cooling etc.

[Britcanuck]

If anyone got any type of reimbursement from Freightliner then they did better than I did. I took mine to a Cummins/Freightliner approved shop who spent the seemingly standard 3 hours on diagnostics before they listened to me that it was the fan clutch. The supply chain seems to be that Cummins builds the engines and sells them to freightliner who sells their complete chassis to the motorhome builder who specifies side or rear radiator. That's when the Horton fan get added. You can see the opportunities to pass the buck. It's going to cost US$2500 or C$3500 if you let them go through the diagnostic process so just quote Freightliner Service Solution 3737 (which the consumer can't access) and tell them to replace the fan. A good HD mechanic can reach the fan clutch and feel whether it's leaking oil. I have had mine replaced just over a year ago and I think it's going again.

[deasnealy]

I spoke with FL hotline. They suggested a tie a pillowcase to the rear fins of the coach and then tap up the RPM's to around 1100 using the cruise function at idle. Then pull the fuse to the clutch fan and see if the pillow blows more violently. If so the clutch may not be the issue. What if I pull the fuse and get no change at all. Could the problem be a simple connection issue or wiring ground issue? I would hate to get a new fan or clutch and all I needed was a jumper to determine that the wiring had been shorted. Has anyone ever heard of the problem is a connection or shorted circuit board?

I will be testing this am and will follow up.

[bobguigley]

We had the fan clutch replaced on our 2010 Damon Astoria about 4 years ago.

Then this past December we started overheating again and after pulling that fan fuse the fan began working again okay. The Gaffney service center installed what they called a "guard dog" . Everything fine now.

The question that I failed to ask and you should ask FL tech support is: How is the "guard dog" better than just running it without that fan fuse?

[deasnealy]

I am thinking about just replacing the unit with the Source Engineering After Market Turbo Direct Drive Fan. Just wondering how many have done this and had long term success. It appears that even after the Horton clutch is replaced with a newer model they are still failing.

[Britcanuck]

I guess the pillow talk test is worth trying. Does anyone know where the fuse for the fan is located.

[bobguigley]

The fan fuse on our MH is in a fuse box in the compartment with the shore power cord. There are about 10 other fuses in that panel/box such as turn signals, lights and brake line for the trailer wiring connector.

[bobguigley]

I suggested just that idea to the tech that installed the guard dog. He said that the Horton fan clutches that have been built more recently have been more reliable.

It just baffles me that they would install this fan clutch instead of direct drive in the first place, especially when it is such a critical item to keep from overheating. I'm sure there are some engineers at FL thinking the same thing since these fan clutches have created such a big problem.

[deasnealy]

My Fuse box is located in passenger rear storage. 4 screws undo it and its a 5 amp screw labeled on the inside of the cover.

[Britcanuck]

Thanks to all re location of fan fuse. I know that fuse panel well, If you tow and have turn signal problems that's the go to place. I've never looked for fan fuses there before but will try the pillow trick and see what happens. I sure hope it isn't failing again after being replaced 13 months ago. To be on the safe side and eliminate other reasons for overheating (again) I just had radiator cleaned and thermostat replaced. Antifreeze is good. I know that most HD mechanics are straight up guys but when they start talking about faulty temperature senders it makes me think that they are grasping at straw.

[Superbike]

I have this problem on a Damon Astoria. Can you give me any details as to where I can get a direct drive fan. I am located in the U.K. And the Motorhome is in Germany

[Britcanuck]

Originally Posted by Superbike

I have this problem on a Damon Astoria. Can you give me any details as to where I can get a direct drive fan. I am located in the U.K. And the Motorhome is in Germany

I haven't tried the pillowcase trick yet but if your temp gauge suddenly shoots up to the red area and the coach starts to shut down then the clutch fan is definitely suspect. The bottom line is the fans are - in the nicest terms-not very good. I had mine replaced last year and going from home in BC Canada to California no problems. On the way back she indicated overheating 3 times. Last time was Weed CA with a few miles to go before the Siskiyou pass on the Oregon border I was sweating. But it never did it again. Back home the local FL dealer checked the fan and said it was fine. I've had coolant changed, radiator area clean of debris(there wasn't any) and in a couple of months will be making the pilgrimage south to escape those Canadian winters. I just don't want any surprises while pounding down I-5 but I don't know what else to do and neither does the FL shop. A direct drive fan is an option but it will probably rob you of some hp. If you have the 340hp motor then you don't want to lose much power. There was an article on one of the forums that spoke to a direct drive but you'll have to do some Googling to find it.
Good luck

[Marionberry]

You might check Source Engineering in Coburg, Oregon (541) 343-0293. I
would suggest a visual check on the intake side of the radiator to be
sure it is not clogged with debris before doing expensive repairs.
https://www.google.com/maps/place/So...4d-123.0532271

Good luck
Marionberry

[Paladin76063]

My 2010 Berkshire 390bh required a new clutch at 14K. Just took it down to Galveston, twice, once towing; no issues. I paid for the replacement as Freightliner and Forest River just point fingers at each other. The FL service bulletin is simply a procedure to diagnose the problem. This issue is well known in the industry and should be a recall item. Forest River and Freightliner should stand up and and fix the issue and in the interim tell customers how to pull the clutch fuse in case of emergencies.

[tacaem]

Originally Posted by teptraveler1

Thanks to the posts regarding the Freightliner Service Solution 3737, Horton fan clutch intermittent overheating issue. Originally took MH to Freightliner where they steam cleaned the radiator, stated that everything was OK. Which is wasn't. Returned to them where they than spent 3.5 hours of diagnostics at $175 per hour and stated it 'could' be a sticking thermostat. They changed thermostat and coolant, stated everything was OK. It wasn't. After spending $2300 and still having overheating issues I took it somewhere else. With the info from this forum in hand I convinced them to replace the fan clutch. Have only had it on about a 120 mile test drive since picking it up, but so far no overheating. Thanks to all who posted regarding this issue. And unless I am on the road and have NO other options, my motorhome will never see another Freightliner facility.

How much did it cost for parts and labor? Did the radiator have to be removed and where did you end up taking it?