Stranded in Baha Serpentine Belt

[Dwight Lindsey]

I just tried to climb out of Bahia de Los Angeles in Baja and dramatically overheated.  The engine de-rated and I got a STOP light on the dash.  I managed to pull over and am stopped on a steep climb above the bay. 

I found a piece of the serpentine belt  . . . so that is the issue.

I'm stuck here at least until the unit cools down.  I hope I can get turned around and back off the mountain later.

I'll search the files to try to find the part number and information for the serpentine belt, which I'm sure I can't find here in this little town.  Meanwhile if someone can give me a shortcut to the part information, I'll be grateful.

I've got Starlink setup, so I can get internet while I'm stopped here.

Dwight

05 Knight ISC 330

[jacwjames]

I think my belt PN is listed in my manual in a table toward the back of the book

[Dwight Lindsey]

OK, I've got the remnants of the belt and my manual says Dayco 3911581, which seems to agree with a 2001 Diplomat from the parts list.

We have the entire belt, the ends match up.

I'm thinking that something seized up, probably the dash air compressor.  I had noticed that we weren't getting good cooling from the dash.

I'm not going to get that replaced here, so I'm thinking of a shorter belt that bypasses the dash air compressor, if that is the problem.

Dwight

Has anyone done this before?  What length would a shorter belt be?  It's an 8 rib belt

 

[waterskier_1]

According to your Owners Manual, the A/C belt is a Dayco 15465 and the Alternator Belt is a Dayco 3911581.  This would imply you have two belts, one likely just for the A/C and the second for the alternator and water pump.  If this is the case, I doubt it was the A/C compressor that froze up, unless that belt also broke and took out the alternator belt.

  -Rick N.

Casa Grande, AZ

[jacwjames]

That is the same belt this is on my 350 ISC 

But my compressor is not driven off this belt, I have a smaller belt for it.  Yours, I would think would be the same. 

If something froze up it would probably be your alternator, other possibility it could be your water pump or idler pulley. 

Best thing to do is to crawl under and confirm or open the rear hatch and put your hands on the alternator pulley, water pump, and idler. 

[Dwight Lindsey]

OK, it does seem as if there are two belts DAYCO 14565 for the AC and DAYCO 3911581 for the alternator, which must run the water pump as well.  I just got turned around and the temperature didn't redline during that short turnaround.  I'm letting it cool down again before trying to get down the mountain about 2 miles.  I'll try to get under the coach and feel the alternator, idler and water pump after I'm off the mountain.

I can live without the alternator, to get home.  I can't live without the water pump and fan running.  Is the fan direct drive?  Or is it on a belt.  No mention of a "fan belt" in the manual

 

Dwight

[jacwjames]

There is one belt that drives the water pump and alternator and assume the fan. 

I have a side radiator with hydraulic fan so not sure on your rig. 

[96 EVO]

You 'can' live without the alternator producing power to get home. You can't live without it's pulley spinning!

[Dwight Lindsey]

So I've got an update, and a puzzle.  We took the motorhome to a local mechanic, Sammy,  in this very small town on the bay of Los Angeles, population between 800 and 1000, depending on how many Gringos are here.

My manual says that I should have two belts, a DAYCO 14565 for the AC and a DAYCO 3911581 for the alternator.

Sammy is sure that there's only one tensioning idler and that there's only one belt.

The DAYCO 39911581 is, according to my google search, 69.75 inches long.

We measured the broken belt, which we have.  The ends match, so we have all of the belt.  It's 82 inches long. 

So without being an expert on idler pulleys, I think he's right.

He says that the dash air compressor is seized up and the alternator and water pump are fine.

So now I need to sort out how to get a shorter belt, that will run the water pump, fan and alternator.  I wonder if it's the 69.75 inch DAYCO 3911581

I'm going to need to drive something like 4 hours in each direction, even if they have the belt and if I get the wrong one, we'll need to repeat the process.  So I might try buying all the suspect sizes.

Once we get a belt or belts I don't personally know how to arrange it on the pulleys.  I'd appreciate any advice and especially diagrams showing how to put the belt on.

Dwight

[Ivan K]

Can you route the broken belt the shorter way, move the tensioner where it should be, mark the belt and compare the lenght? Probably not that easy with rear radiator but maybe doable? I know an inch makes a big difference with belts.

BTW, is it the compressor clutch that's seized along with the compressor or is it free with AC off?

Edited March 7 by Ivan K

[jacwjames]

The air compressor is tensioned with a bolt/stop nut.  It uses (on mine) a smaller V belt.  I doubt the pulleys would line up to be able to use a single belt.

I'd have him try and put the 3911581 belt on

 

[waterskier_1]

As Jim posted, the A/C Compressor belt is tensioned by the compressor mounting.  The idler pulls is for the alternator and likely the water pump/fan.

  - Rick N 

 

[Dwight Lindsey]

My air conditioner compressor has a pulley for the 8 rib serpentine belt

[jacwjames]

So someone reconfigured the belt so that it powers the AC. 

BUT you should be able to use the belt listed in the manual and be able to install and just bypass the compressor. 

[cbr046]

I Googled "cummins isc serpentine belt routing" and got lots of hits, but they weren't much help . . . . .

Crazy idea:  Take a string and route it like the serpentine belt with AC NOT tensioned by the tensioner.  Compare that length (A) with the length of the broken belt (B).  This gives a comparison of a "straight line measurement" with that of proper length belt.  Then route the string without routing around the AC.  We'll call this measurement (C).  Subtract C - (B-A).  That's my best guess approach to spec'ing a belt length without AC.  Make sure you have the right number of ribs and shape ('V' vs round, etc).  Good luck. 

- bob

[Dwight Lindsey]

We're working on getting some belts. Difficult here in Baja.  Meanwhile I'm starting to think about replacing the dash air compressor.  My RV Data Card says dash air conditioner SCS 1689747, which is not made anymore.  Suggestions?

[Dr4Film]

Not sure if this diagram will help at all.

[Bykerboy]

I have a 2006 Knight with the ISC 330.  The owners manual says two belts, this is not correct.    There is a single belt that drives all of the components including the A/C.  All adjustments are done with tensioner.   I used Napa part number NAPA 25-080830.   I would do what @cbr046 suggested and measure the length you need with a piece of string.   I would also suggest buying a slightly longer and slightly shorter belt and use the one the fits best when bypassing the A/C.   If the belt is too short you will never get it over the tensioner.  You can always return the unused belts (at least here in the US).

[Scotty Hutto]

Dwight,

Just as confirmation of what you mention above, the owners manual for my 2006 Diplomat shows separate belts for the alternator and AC compressor, but it came from the factory with one single serpentine belt.

Would it be possible to get the clutch on the AC compressor to unlock (it uses 12v to “lock” the clutch), disconnect the clutch wiring, and leave the compressor in place?

Finally, as for the AC compressor, it’s likely a Sanden.  See if you can find the (typically) 4 digit part number on the compressor label.  I was able to find one for my coach from Aero Climate Control in Rockwell, TX phone +01-972-772-5506 or online at https://www.acparts.com/.  They have stock of older Sanden compressors that are no longer produced by Sanden.

Good luck!

[96 EVO]

29 minutes ago, Scotty Hutto said:

 

Would it be possible to get the clutch on the AC compressor to unlock (it uses 12v to “lock” the clutch), disconnect the clutch wiring, and leave the compressor in place?

 

Makes sense to me, unless the pulley itself is seized.

[RNMCBR]

Dwight,

I have a 07 Diplomat with a ISL8.9. My engine uses one belt to drive all the accessories. Yours may be the same as mine. Here is a picture.

You might also be able to verify it with Cummins Quickserve. 
 

Roy
 

[bborc555]

I have an 07 Knight with the 330 isc and it has only one belt

[Cevin Waffle]

I just had the same problem and bypassed the compressor until I replace it. I have a 2008 Diplomat with the ISL 400, rear radiator,  but sounds like the same belt path. I used a Gates #K080734HD, 73" and worked fine. Goes right under the compressor to the alternator. You should also look at the belt tensioner and fan hub bearing, changed both of these at the same time.

[Dwight Lindsey]

We got some belts in San Felipe today.  8 hours of driving.  We did get an 82 inch belt, which should work if we can get the AC compressor pulley to spin.  We'll try to free up the clutch tomorrow.  We also got a 69.5 inch belt and a 70 inch belt.  A 69.75 inch belt is what the coach manual says is one that should do the water pump, fan and alternator in a 2 belt configuration.  So one of those belts may work to get water pump fan and alternator to work.  We also got a couple of shorter belts, which is a Hail Mary pass that might let us just run the fan and water pump, which will get me home.

Any hints about belt routing would be much appreciated.  

Dwight

Edited March 9 by Dwight Lindsey

[Benjamin]

Show Sammy the diagrams that Dr4film posted above, he'll figure it out.  I bet he could move the idler to make a wide range of belts work if he had to.  I'd guess the idler is not needed with bypassing the AC compressor.  The clutch on the AC compressor is usually replaceable without replacing the compressor, and should spin fine with the power off even if the compressor is locked up solid.