Community Forums

BOTEWCC · 02-02-2020, 12:14 AM

Quote:

Originally Posted by BOTEWCC

Replacing the fan clutch with a new one would seem to be the right answer EXCEPT for so many people having more issues with replaced fan clutches that were not that old. I’d hate to have the work done only to have this issue happen again In 20-30k miles

Ok, so I bit the bullet and had my fan clutch assembly replaced. As long as they were in there, I had a new water pump and serpentine belt replaced as well. Also had new coolant and the system pressure tested. I’ve driven it about 200 miles now and everything is working normally.

This latest info about changing the relays might come in handy and would have been something to try before having the fan clutch replaced, so I’ll keep that in mind should the problem arise again.

For now, I have peace of mind again and just wanted to shout out a “thank you” to all those people who took the time to chime in with their experiences and advice!

scooterbob · 02-03-2020, 08:03 AM

Quote:

Originally Posted by ziaptrn

The part number for the fan clutch in question is:
Fan Clutch: Horton HOR 9805002

I spoke with a Cummins rep at length when we were in Quartzsite a few weeks back. He was an engine guy and wasn't aware of the problem (they all say that) BUT, he did have a suggestion.
Based on what I was telling him, and especially the episodic nature of the problem plus the fact that stopping and re-starting seems to temporarily "fix" the problem, he said that it sounds like a sticking relay to him. He said that the relays get old, and also get water inside of them (yes, even in the desert where we live - as I pointed out), but that one idea would be to replace the relay for the fan clutch.

The relay is on the PDM (power distribution module) box that is tucked away in the electric cord bin behind a non-obvious removable panel as discussed previously in this thread.

The Fan relay is #R10 and it is the second relay from the right on the bottom row. My rig has 10 of the identical relay all plugged in to the PDM module.

I replaced the fan clutch relay #R10 and drove several days back from Quartzite without a single hitch and what I would have called totally normal performance. The rig temp rises a bit going up hills and drops going down - but zero overheating and the fan shuttled on and off appropriately.

So. While I'm a bit irritated that perhaps an $11.00 relay (2 for $9.00 on Amazon), I'm hopeful that this may have been the problem all along.

If this doesn't turn out to be the final fix and the problem recurs, I'll post again.

John

Do you happen to no the part # for that relay ? I see a 3 pack on amazon but not the same part number as you posted.

Superbike · 02-08-2020, 07:17 AM

Ok, I’ve been reading all the very helpful posts regarding the intermittent fault on these fans. I am on my 3rd replacement now and this one has just began its usual antics! Noticed it overheating but very close to my destination in cold weather so I got there with no warning lights. Went to the rear of coach - zero air blowing. Turned engine off and back on - blowing like a helicopter!
My questions are: on start up the fan is blowing very hard even from cold???
So it seems it’s either flat out or off?
Does this mean another fan, or is it a relay? Sensor? Switch?
Many thanks, Mark.

ziaptrn · 02-08-2020, 08:28 AM

Hi and thanks for participating in this ongoing saga. I'm getting to be sort of like a dog with a bone - or maybe it's more of a vendetta?

In our experience.... 1. When "acting up", the fan does not blow on start up. Verified this many times, and it's more common when weather is cold as you noted. The scenario is - a) start up b) fan not running (no air movement) when you walk around back c) begins to overheat evidenced by engine temp rising above 200 accompanied by rising transmission temp to 170-80-90 d) pull over and shut engine down e) count to 4 seconds with engine off f) re-start g) walk back around and fan is blowing like a hurricane after re-start and temps normalize nearly immediately h) engine temp drops rapidly to 190s following by transmission temp to just around 140 degrees unless pulling a hill etc when transmission temp is expected to rise depending on load

Latest fix (rig is on 3rd fan clutch and has Horton Guard Dog installed) was to replace the relay for the fan clutch. After replacing the relay and driving 300+ miles there was no overheating and no abnormal operation. That being said- it has behaved this way with multiple "repairs" such that it seems to have fixed the issue only for it to return.

Freightliner and Winnebago both say that they have "never heard of such a strange thing" and they can't reproduce it. (2 different Freightliner shops, including the mother ship at Gaffney SC said this). Cummins says for their part the signal is either on or off from the engine, and that is working properly, and that the issue must be with the temperature regulation equipment and operation which they do not install.

And as just a little background: Yes the radiatior is clean (it's new), yes the CAC is clean (it was thoroughly cleaned when the radiator was replaced), yes the thermostat is ok - it was replaced along with the new radiator and all new hoses when that work was done recently. The radiator was replaced because it was rusted and leaking.

That's my story and I'm sticking to it. For now, the issue appears to be resolved yet again with the relay replacement. I will post a follow-up as temps warm and we travel more to have more opportunities for overheating :-)

BOTEWCC · 02-14-2020, 02:11 PM

Quote:

Originally Posted by ziaptrn

I realize now that I could/should have posted a pic!
I'm attaching a photo of the box opened. Fuse #15 for the fan clutch has been pulled (now replaced with a switch), and Relay #10 is the one immediately to the left.

Both are circled in red.
Hope this helps.....

Thank you for the photos but I have a 2008 Fleetwood Expedition and the "inconspicuous box with a removable lid in the power cord compartment) was not found. I did find a box with a removable lid, but couldn't find the 5 amp fuse or the relay. So, if anyone out there with a Fleetwood coach knows where to find said fuse and relay, could you post a description with some pics please?

Thanks!

RichKimball · 02-15-2020, 07:54 AM

Quote:

Originally Posted by BOTEWCC

Thank you for the photos but I have a 2008 Fleetwood Expedition and the "inconspicuous box with a removable lid in the power cord compartment) was not found. I did find a box with a removable lid, but couldn't find the 5 amp fuse or the relay. So, if anyone out there with a Fleetwood coach knows where to find said fuse and relay, could you post a description with some pics please?

Thanks!

Not so elusive. Passenger side 2nd basement compartment from the rear. Don't have a pic handy with cover off...but I thought there was one in the thread. Cover has location labels.

scooterbob · 03-04-2020, 06:46 AM

UPDATE
just to give you a heads up on my adventure.
I had put in a switch for the 5am fuse and replaced the relay that we talked about. Well this am I left Rockport Tx. with the switch in the normal position (on) went 10 miles and heated up to 200 degrees. Pulled over flipped the switch, started it up and made no difference. I went down the road 2 more times and still the same. The last time I run until the high heat and check engine light come on. Shut down waited about 5 min. started up and it was fine for the redt of the day, 192/194 normal. There has to be a sensor someplace that controls the fan. I am here in Beaumont Tx. until Thursday morning, and hopefully with the switch in off position it will stay cool.
Will keep you posted.

scooterbob · 03-04-2020, 06:53 AM

I went to Freightliner this morning talk with them for over an hour no one was able to locate that service bulletins 3737.
He suggested there is a sensor on this side of the engine block near the water jacket that senses when the water is hot enough it turns fan on/off.
He suggested I bring it in so they could put it on their computer to see if there was a fault code however this morning the fan is running with the fan switch in on position , "that on position would be like if there is a fuse in the socket"
I would sure like to locate that sensor however my motorhome is a rear radiator and it's impossible to see it without lifting the bed or looking underneath.
If I come across any additional information I will let you know and hopefully you will do the same

f14av8r · 03-05-2020, 05:26 AM

Quote:

Originally Posted by scooterbob

I went to Freightliner this morning talk with them for over an hour no one was able to locate that service bulletins 3737.
He suggested there is a sensor on this side of the engine block near the water jacket that senses when the water is hot enough it turns fan on/off.
He suggested I bring it in so they could put it on their computer to see if there was a fault code however this morning the fan is running with the fan switch in on position , "that on position would be like if there is a fuse in the socket"
I would sure like to locate that sensor however my motorhome is a rear radiator and it's impossible to see it without lifting the bed or looking underneath.
If I come across any additional information I will let you know and hopefully you will do the same

When you say you spoke with Freightliner, are you talking about your local dealer? If so, I suggest you contact the Freightliner Custom Chassis helpline and talk with them, not the local dealer. The number is 800 FTL-HELP. Have your VIN ready. They should be able to find the Service Bulletin 3737. I assure you that it exists.

Hdwick · 03-06-2020, 04:32 AM

Bob. It is not a service bulletin, it is a service solution they are 2 different I look to see if I still have a copy of this, I had mine fixed the hub actually broke and the clutch was bad on the fan.

f14av8r · 03-07-2020, 05:38 AM

Quote:

Originally Posted by Hdwick

Bob. It is not a service bulletin, it is a service solution they are 2 different I look to see if I still have a copy of this, I had mine fixed the hub actually broke and the clutch was bad on the fan.

That is correct - it is a Service Solution, not bulletin. My mistake. FCCC should still be able to locate it for you.

scooterbob · 03-07-2020, 05:49 AM

Has anyone installed the GUARD DOG ?

dirt40 · 03-10-2020, 08:01 PM

Subscribing to this thread. We have had some overheating issues since we bought ours a year ago. Many repairs by the dealer and finally our local FL.

scooterbob · 03-11-2020, 05:30 AM

Quote:

Originally Posted by Hdwick

Bob. It is not a service bulletin, it is a service solution they are 2 different I look to see if I still have a copy of this, I had mine fixed the hub actually broke and the clutch was bad on the fan.

Was you successful in locating a copy of the service solution 3737