ISC Fan Clutch Replacement $4000+ ?

[elhajj33]

Hey all,

We have a 2009 Fleetwood Excursion 40x with a cummins ISC engine. Yesterday afternoon, while driving down into Sedona on I-17, our serpentine belt snapped. As it snapped, it broke the wiring on the fan clutch.

Reliable Diesel, out of cottonwood, just left a few minute ago. The quote I got has the following:

Fan Clutch $2040
Coolant: $179
Belt: 92
Labor (14hrs): $1470
Fetch Parts from Phoenix: $500.

This is our first mechanical breakdown and we're having a bit of sticker shock. The numbers seem up there. Thought I'd get some advice. Any mechanics out there?

[elhajj33]

all good, i'n by no means an expert UsersManual 🙂

by the way, definitely an call this one solved. Installed the fuse and drove over 5 hrs through mountains to Yuma, AZ (our last stop before San Diego where we'll be until the end of Jan before getting back on the road again.

The coach performed perfectly and I did see the temp fluctuate up and down indicating the fan was, in fact, cycling. Alright, calling it solved (again).

Happy thanksgiving all!

[usersmanual]

elhajj33 wrote:

usersmanual wrote:

11178adm wrote:
if the fan never turns off you may have a problem with the a/c high pressure curcuit, it could be a switch or wiring issue

no

Actually there's some truth to that statement.

This from cummins (linklink):

With the A/C Vehicle Speed Control feature option enabled, if the fan is operating due to A/C pressure input, it will disengage in the follow manner:

Below 6 mph: At vehicle speeds of less than 6 mph, once activated, the fan will continue to run until the vehicle speed exceeds 6 mph. or the engine is shut down.

Between 6 and 30 mph: If the vehicle is traveling between 6 and 30 mph and the fan is activated, it will disengage after it has run for at least the length of time defined by the Fan Control A/C Pressure Switch Timer parameter.

Above 30 mph: At vehicle speeds above 30 mph the fan will disengage as soon as the pressure switch no longer indicates a need for fan cooling. Subsequent input from the pressure switch will cause the fan to activate and deactivate as necessary.

This would possible be the case when the AC condenser was attached to the rad and the engine cooling fan also cooled the AC system
most DP I have owned and seen have a stand alone electric fan that cools the dash AC system condenser
therefore that's why I said no

[elhajj33]

usersmanual wrote:

11178adm wrote:
if the fan never turns off you may have a problem with the a/c high pressure curcuit, it could be a switch or wiring issue

no

Actually there's some truth to that statement.

This from cummins (linklink):

With the A/C Vehicle Speed Control feature option enabled, if the fan is operating due to A/C pressure input, it will disengage in the follow manner:

Below 6 mph: At vehicle speeds of less than 6 mph, once activated, the fan will continue to run until the vehicle speed exceeds 6 mph. or the engine is shut down.

Between 6 and 30 mph: If the vehicle is traveling between 6 and 30 mph and the fan is activated, it will disengage after it has run for at least the length of time defined by the Fan Control A/C Pressure Switch Timer parameter.

Above 30 mph: At vehicle speeds above 30 mph the fan will disengage as soon as the pressure switch no longer indicates a need for fan cooling. Subsequent input from the pressure switch will cause the fan to activate and deactivate as necessary.

[elhajj33]

wildmanbaker wrote:
I have been following your post, and like Jim and others, am glad you got it figured out, without getting speared. You got good advice and help from the forum, and this is how it is supposed to work. Everyone's opinion is important, no matter how outrageous it may seem. Proud to be a member!

Thanks Wildman; even though not all the advice was spot on, it did help point me in the right direction. What might be spot on for one engine/configuration won't be for another. But, at least I had questions to ask Cummins, Freightliner and Horton.

By the way, even the info i got from freightliner was slightly incorrect. After I got the fuse in and started the coach up, the fan kept running for several minutes- significantly longer than the 30secs freighliner told me it would. Nonetheless, it did eventually die down to where there was barely any air flowing out of the radiator.

I set the cruise control to keep RPMs at about $2000 while we were parked and I did see the temperature fluctuate up and down to keep the engine at about 176 degrees (i might be a degree or two off.)

When the coach first fired up the fan sound was very loud. After it got up to temp, you couldn't hear the fan, but there was still some airflow from the radiator - albeit very minor. This tells me the clutch is engaging and disengaging.

I know this is a lot of detail, but perhaps it'll help someone who might find this post in the future.

Thanks again to everyone! Leaving Arizona in a few and heading to California with a fully functional coach!

[usersmanual]

11178adm wrote:
if the fan never turns off you may have a problem with the a/c high pressure curcuit, it could be a switch or wiring issue

no

[11178adm]

if the fan never turns off you may have a problem with the a/c high pressure curcuit, it could be a switch or wiring issue

[wildmanbaker]

I have been following your post, and like Jim and others, am glad you got it figured out, without getting speared. You got good advice and help from the forum, and this is how it is supposed to work. Everyone's opinion is important, no matter how outrageous it may seem. Proud to be a member!

[usersmanual]

elhajj33 wrote:

Ivylog wrote:
Your fan should not come on until the water temperature gets above 185°. You have a water temperature sensor probably close to the thermostat that is normally open until it senses 185°. When it closes it provides the ground to close a relay that provides the 12 votes to magnetize the fan clutch.

got to the bottom of it! I called horton and confirmed that the clutch is engaged at zero volts- that was a good sign as the clutch was not getting voltage. I also freightliner; they confirmed the fan come on as soon as the engine starts and stays on for about 30seconds until the ECM sends a signal to the clutch.

Finally, Freighliner suggested the fan clutch fuse might have blown. This seemed very likely since the serpentine belt did snap the wires.

I checked the fuse and, wouldn't you know it, it had blown! I just need to run out now and get a 5A mini fuse (it's one of the ones I don't have onboard).

i was so relieved that it wasn't the clutch! I'll report back when it's all up and running.

Thanks everyone for helping me out!

sounds great;; glad u figured it;; glad u never followed the bogus suggestions on here about your fan operation

[elhajj33]

Ivylog wrote:
Your fan should not come on until the water temperature gets above 185°. You have a water temperature sensor probably close to the thermostat that is normally open until it senses 185°. When it closes it provides the ground to close a relay that provides the 12 votes to magnetize the fan clutch.

got to the bottom of it! I called horton and confirmed that the clutch is engaged at zero volts- that was a good sign as the clutch was not getting voltage. I also freightliner; they confirmed the fan come on as soon as the engine starts and stays on for about 30seconds until the ECM sends a signal to the clutch.

Finally, Freighliner suggested the fan clutch fuse might have blown. This seemed very likely since the serpentine belt did snap the wires.

I checked the fuse and, wouldn't you know it, it had blown! I just need to run out now and get a 5A mini fuse (it's one of the ones I don't have onboard).

i was so relieved that it wasn't the clutch! I'll report back when it's all up and running.

Thanks everyone for helping me out!

[Ivylog]

Your fan should not come on until the water temperature gets above 185°. You have a water temperature sensor probably close to the thermostat that is normally open until it senses 185°. When it closes it provides the ground to close a relay that provides the 12 votes to magnetize the fan clutch.

I would start by finding that sensor and taking the wire off of it and then crank the engine and see if the fan still turns. Chances are it will not so you need a new sensor. If it still turns then you need a new relay.

If you have to replace the sensor, I have found that you can still use a single wrap of Teflon tape on the beginning of the threads without loosing the ground you need. Use too much and the sensor will not work... cannot go to ground. Plumbing pipe dope is a safer choice if you can find some.

[rgatijnet1]

Reliable Diesel might not care about the BB or C of C complaint but if you post your experience on this website, it may protect other RV owners from getting ripped off. RV Service Center reviews
I think that Reliable Diesel is out of Rimrock, AZ which is near Cottonwood, AZ.

[usersmanual]

elhajj33 wrote:
Quick update: The fan clutch is electrically operated. Got another mechanic out here today and he was able to splice together the wires and install a new belt. Add some coolant and we were just a little over $1000 mostly on labor.

I filed a complaint with GoodSam about Reliable Diesel and will be reporting them to the Chamber of Commerce. Basically, they try to get you to get towed to their lot whenever you break down and then you're held captive until you pay whatever estimate they give you or pay to get towed to another shop. This way you have to gamble on whether or not the 2nd estimate will be the same as theirs.

Now, here's the thing: the fan comes on as soon as the engine turns over. I'm not sure, but we may have a bad fan clutch.

The thing is: that's how it's always been since we bought the coach- so i'm not sure if I have a bad clutch or not...

The coach does drive well and the temp does stay cool. I just have no way of knowing if I have a fan clutch issue or not.

good to hear for sure $1000 still sounds very high but its a lot
better than yesterdays estimate

[cudntherd]

Our ISB had the A/C clutch seize up and snapped the serpentine belt that cut the fan clutch wire harness. new parts were: New A/C clutch ,compressor, receiver dryer, new belt and Horton fan clutch wire harness and anti-rotation mounting bracket. The fan clutch was not damaged and was not replaced.
All work was performed by Freightliner of AZ. Tucson. Total cost for parts and labor was less than the price you are being quoted.

Time for a second opinion.

[elhajj33]

Quick update: The fan clutch is electrically operated. Got another mechanic out here today and he was able to splice together the wires and install a new belt. Add some coolant and we were just a little over $1000 mostly on labor.

I filed a complaint with GoodSam about Reliable Diesel and will be reporting them to the Chamber of Commerce. Basically, they try to get you to get towed to their lot whenever you break down and then you're held captive until you pay whatever estimate they give you or pay to get towed to another shop. This way you have to gamble on whether or not the 2nd estimate will be the same as theirs.

Now, here's the thing: the fan comes on as soon as the engine turns over. I'm not sure, but we may have a bad fan clutch.

The thing is: that's how it's always been since we bought the coach- so i'm not sure if I have a bad clutch or not...

The coach does drive well and the temp does stay cool. I just have no way of knowing if I have a fan clutch issue or not.