Alternator

[Chuck B 2004 Windsor]

I have been on this group since it's beginning in 1998 or so.  I would say that 99% of the members dealing with alternator problems will tell you the easiest way out is to have your alternator rebuilt.  I have seem many members who went with another alternator, especially on the road, wished they had theirs's rebuilt.  JMHO,  Chuck B

[Pampero]

2 minutes ago, Chuck B said:

I have been on this group since it's beginning in 1998 or so.  I would say that 99% of the members dealing with alternator problems will tell you the easiest way out is to have your alternator rebuilt.  I have seem many members who went with another alternator, especially on the road, wished they had theirs's rebuilt.  JMHO,  Chuck B

Like I said, If you are 400 miles away and the rebuilded alternator fails, what do you do?
I know people go to PepBoys to get the Alternator or started replaced. And I saw them going back and back again. Rebuild does not mean "remanufacturer". Rebuild means check and replace what is worn out, could be brushes or voltage regulator. 
Yes rebuild is the easy way out, not the best repair. A new alternator will cost less than $300.00 plus installation, which is a good DIY easy job.

 

[Jvblakeman]

Let me say...... GET YOURS REBUILT. 

This summer, mine went out. I went to USA 1 battery and ordered a new one ($529) and gave them my old one. Brought it home and hooked it up (had to make a new bracket, since it wasn’t identical). It didn’t work..... wasn't charging. So I called them and they said to hook up a wire to excite it (previous one was self exciting) I did that, and it was charging, but no tachometer. I went back and asked for my core. They said they already sent it with the core guy. I told them to call the core guy, and get mine back. 1/2 hour later, they “found” mine. I brought the one back that I purchased, and they gave me a full credit. I then took MY core to an alternator shop, where they replaced the voltage regulator, and one bearing. $75 later, I had a perfect working alternator, and a working tachometer. 

[Chuck B 2004 Windsor]

Good Luck,  Chuck B

[Guest Ray Davis]

28 minutes ago, Pampero said:

Like I said, If you are 400 miles away and the rebuilded alternator fails, what do you do?

 

 What I do is run the generator , it will charge the chassis batteries and keep me going for the entire trip if necessary .

 A rebuild will usually cost approx $200 to $300 and will include bearings  , diodes and regulator .   A repair of the alt could be less .

Edited November 2, 2020 by Ray Davis

[daveyjo]

I have seen the many cautions about buying a replacement alternator vs. rebuilding.  When mine went out in my 2001 Diplomat, they could not rebuild it so they bought a new one.  I cautioned them about the many warnings on the forum, and they went ahead and bought a direct replacement and it has worked wonderfully since then.  The details from my maintenance log are: Replaced alternator ($585) at Johnny’s auto and marine electric (labor $275), Raleigh, NC.  Was a 2824LN-NP Leece Neville (same as bad one), and alternator pulley and 1 cable end. Total $965.66.

I guess one can buy new and have it work.

[Dennis H]

Monacos have always been persnickety about alternators. I bet posts are 90% problematic if replacing the alternator. They are not rocket engines and I'm not an engineer so I can't say why new or re-manufactured ones give us fits. I'm old enough to remember the DC generators with commutators. Now those beasts were irritating but easily fixable. A good repair shop can rebuild your alternator more easily and much cheaper than buying a new one. This is one instance where buying new is not better. YMMV.....Dennis

[Speerfamily]

I have seen folks have issues with after market alternators supposedly because of the additional load we put on them to charge things going down the highway, such as battery banks and fridges, etc..  I had mine rebuilt four years ago with no issue.  If I was on the road and had issues (and I have) I would run the generator so that I don't have to a repair on the side of the road or during a trip. 

[Pampero]

2 hours ago, daveyjo said:

I have seen the many cautions about buying a replacement alternator vs. rebuilding.  When mine went out in my 2001 Diplomat, they could not rebuild it so they bought a new one.  I cautioned them about the many warnings on the forum, and they went ahead and bought a direct replacement and it has worked wonderfully since then.  The details from my maintenance log are: Replaced alternator ($585) at Johnny’s auto and marine electric (labor $275), Raleigh, NC.  Was a 2824LN-NP Leece Neville (same as bad one), and alternator pulley and 1 cable end. Total $965.66.

I guess one can buy new and have it work.

https://www.amazon.com/gp/product/B071HBSZJQ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

3 hours ago, Ray Davis said:

 What I do is run the generator , it will charge the chassis batteries and keep me going for the entire trip if necessary .

 A rebuild will usually cost approx $200 to $300 and will include bearings  , diodes and regulator .   A repair of the alt could be less .

I am very skeptical after many years in my type of business, I know what they do and what they don't. As always we all have different opinions.
So you prefer to pay 200 to 300 dollars for a rebuild and pray that the rebuilder didn't skip any steps and install what you said they install instead of paying $253.00 for a new one?

And if you keep running the engine, remember that the generator still turning, and if the guy didn't replace the "bearings" then you will really get stranded.

Everyone makes a choice in life.

[Speerfamily]

6 minutes ago, Pampero said:

https://www.amazon.com/gp/product/B071HBSZJQ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Yep,, but yours wasn't just any old aftermarket, it looks like you found an exact replacement which is great (except for the price).

[Pampero]

I am sorry, but I don't follow your answer; "except for the price?"

$252.00 is a bad price?

[Romeo84]

20 hours ago, Jvblakeman said:

Let me say...... GET YOURS REBUILT. 

This summer, mine went out. I went to USA 1 battery and ordered a new one ($529) and gave them my old one. Brought it home and hooked it up (had to make a new bracket, since it wasn’t identical). It didn’t work..... wasn't charging. So I called them and they said to hook up a wire to excite it (previous one was self exciting) I did that, and it was charging, but no tachometer. I went back and asked for my core. They said they already sent it with the core guy. I told them to call the core guy, and get mine back. 1/2 hour later, they “found” mine. I brought the one back that I purchased, and they gave me a full credit. I then took MY core to an alternator shop, where they replaced the voltage regulator, and one bearing. $75 later, I had a perfect working alternator, and a working tachometer. 

I'm curious how did the alternator affect your tach?

 

[amphi_sc]

My experience.  Alternator bearings went out so being side radiator easily took the belt off (belt ran alternator and dash air only, nothing else).  Drove 200 miles on Onan generator to bigger city Freightliner.  New exact replacement # shipped in for about $700 as I recall, part only.  Rear radiator so was an easy DIY install except for swapping the pulley.  Couple years later that new one cooked itself when internal regulator went bananas around Fallon NV.  Had choice going back to Reno or continuing to Vegas where we had reservations.  Again took off the belt and again drove about 400 miles to Vegas on the generator to our campsite in town. Had alternator rebuilt by a local shop who replaced field coil, bearings, regulator, etc....pretty much just reused the housing: cost about $275 (and did it in a day). That rebuild has been perfect for several years now. (By the way, tried to have the first one rebuilt by a couple of shops but they say the way it ate itself when the bearings went out made it impractical to rebuild.  Otherwise I'd carry it as a spare I probably would never need...that's the way spare parts usually work for me...)

FWIW

[veraken]

I replaced my 160 amp Leece Neville 2824LC with a 200 amp Delco Remy 28SI. The install was fairly simple, ( I have a side radiator) except on the DR you don't connect the excite wire since it is self exciting. I purchased mine with a extra pulley wheel at:

https://www.qualitypowerauto.com/catalog.php?category=139

I had my old LN rebuilt and carry it as a spare.

3 hours ago, Romeo84 said:

I'm curious how did the alternator affect your tach?

On my alternator, there is a terminal to attach a wire that runs directly to the tach.

 

 

[Jvblakeman]

My tachometer hooks directly to my alternator, but it didn’t work with the new alternator, that why I went back to my old one.  

[Romeo84]

So interesting. The other day my 2000 signature my tach was cutting in and out. Does that mean the alternator is going bad? What voltage should we be getting at the battery with the motor running? 13.0 - 14.0 right?  Going to have to check this out.

 

 

.. man I love this site.

Edited November 3, 2020 by Romeo84

[Jvblakeman]

37 minutes ago, Romeo84 said:

So interesting. The other day my 2000 signature my tach was cutting in and out. Does that mean the alternator is going bad? What voltage should we be getting at the battery with the motor running? 13.0 - 14.0 right?  Going to have to check this out.

 

 

.. man I love this site.

It doesn’t automatically mean the alternator is bad. I would hook up a voltage meter and see if there is any fluctuation, with that. I would also just wiggle the tach wire at the alternator. 

[Ivan K]

51 minutes ago, Romeo84 said:

So interesting. The other day my 2000 signature my tach was cutting in and out. Does that mean the alternator is going bad? What voltage should we be getting at the battery with the motor running? 13.0 - 14.0 right?  Going to have to check this out.

 

 

.. man I love this site.

Mine does it too sometimes, usually right after a cold start up and then it levels up. It did not bother me enough to follow up on it yet since I watch the vitals and RPM on Scangauge at start. Typical voltage reading shows as 14.3V. I know that the alt is sending pulses from section of the stator winding through diodes and they supposed to be at 1/10th of alternator RPM which is proportional to engine RPM. I don't know if amplitude of the pulses would make it jump around like that, it might, it never seems to go below the actual RPM, seems moving between normal and maybe 500 RPM higher until it settles and holds there a minute or so later. I can imagine that the alternator has to work harder after start to replenish the starter consumption. There are no moving parts in the circuit so the first thing I will eventually check is the connections.

 

Edited November 3, 2020 by Ivan K

[Bob Nodine]

31 minutes ago, Ivan K said:

Mine does it too sometimes, usually right after a cold start up and then it levels up. It did not bother me enough to follow up on it yet since I watch the vitals and RPM on Scangauge at start. Typical voltage reading shows as 14.3V. I know that the alt is sending pulses from section of the stator winding through diodes and they supposed to be at 1/10th of alternator RPM which is proportional to engine RPM. I don't know if amplitude of the pulses would make it jump around like that, it might, it never seems to go below the actual RPM, seems moving between normal and maybe 500 RPM higher until it settles and holds there a minute or so later. I can imagine that the alternator has to work harder after start to replenish the starter consumption. There are no moving parts in the circuit so the first thing I will eventually check is the connections.

 

I am guessing that the shape of the pulse will be dependent on the alternator load. It is quite possible that the circuit that is triggering on that pulse is affected by the shape of the pulse causing a difference in the reading. I would call it a poor man's tach and prefer the Scangauge reading which is most likely from a Hall effect device somewhere on the engine. 

[Guest Ray Davis]

If you have an electronic engine your tach is not driven by the alternator .   It will be operated from the computer (  ECM )  .

I'm not sure when the change was made from mechanical engines to electronic but probably in the mid to late 1990s .

My guess is if the alt is charging it is putting out pulses , that's what the tach counts  , that's why the size of the pulley is important .

 

Edited November 3, 2020 by Ray Davis

[Romeo84]

Never knew that! Awesome fast response. Thanks for the info! So much helpfull useful information on here!

[vanwill52]

On 11/3/2020 at 3:11 PM, Ray Davis said:

If you have an electronic engine your tach is not driven by the alternator .   It will be operated from the computer (  ECM )  .

I'm not sure when the change was made from mechanical engines to electronic but probably in the mid to late 1990s .

My guess is if the alt is charging it is putting out pulses , that's what the tach counts  , that's why the size of the pulley is important .

 

Ray, perhaps I am misunderstading your post, but even though my wiring diagrams show a tachometer output on the ECM, the tach will not operate if the alternator does not have a tach output.  My engine is a 1999 (engine, not coach) ISC and the ECM wiring diagram clearly shows a tach OUTPUT, but I've not been able to find where it goes in the coach.  But if the tach output of the alternator is disconnected, the tach is dead.  That was the same on my 1993 with a mechanical 8.3 engine...disconnect tach OUTPUT on alternator, and tach is dead.  Both coaches had identical (or nearly so) Leece-Neville alternators.

I do not know this from personal experience, but I assume the ECM gets its engine RPM data from the crank angle sensor.  Since that would be the most accurate, I have no idea of the reasoning behind using the alternator in any way for the tach.  That may have been a Monaco decision as to which output (ECM or alternator) to use for the tach signal.  I just know the tach will not operate without a tach connection to the alternator.  And a frequent diagnostic clue is that when your tach suddenly stops working, check to see if the alternator is still charging normally.

Paul Whittle was among the first to adopt the Blue Sea ML-ACR when replacing his alternator on a 2004? Sig with ISC-525. I believe he replaced the alternator with a Delco-Remy 28si which had a tach output.  Perhaps he will chime in about his experience with the tach's accuracy after the swap.

[Guest Ray Davis]

3 hours ago, vanwill52 said:

Ray, perhaps I am misunderstading your post, but even though my wiring diagrams show a tachometer output on the ECM, the tach will not operate if the alternator does not have a tach output.  My engine is a 1999 (engine, not coach) ISC and the ECM wiring diagram clearly shows a tach OUTPUT, but I've not been able to find where it goes in the coach.  But if the tach output of the alternator is disconnected, the tach is dead.  That was the same on my 1993 with a mechanical 8.3 engine...disconnect tach OUTPUT on alternator, and tach is dead.  Both coaches had identical (or nearly so) Leece-Neville alternators.

I do not know this from personal experience, but I assume the ECM gets its engine RPM data from the crank angle sensor.  Since that would be the most accurate, I have no idea of the reasoning behind using the alternator in any way for the tach.  That may have been a Monaco decision as to which output (ECM or alternator) to use for the tach signal.  I just know the tach will not operate without a tach connection to the alternator.  And a frequent diagnostic clue is that when your tach suddenly stops working, check to see if the alternator is still charging normally.

Paul Whittle was among the first to adopt the Blue Sea ML-ACR when replacing his alternator on a 2004? Sig with ISC-525. I believe he replaced the alternator with a Delco-Remy 28si which had a tach output.  Perhaps he will chime in about his experience with the tach's accuracy after the swap.

Van , I have no personal experience with the tach and alternator issue , I was really parroting what I remember Bill D telling people many times .  It is interesting that you have a 2000 model yet your tach is driven by the tach .  Do you have a mechanical engine ?  If you do then that is the answer but with that said I see no reason why an electronic engine couldn't use the alt to drive the tach .  Am I wrong is assuming that ?  You know what they say about assuming anything .   I have always believed that mechanical engine  ( alt / tach ) electronic engine ( ecm / tach ) I think that is what Monaco did for the most part .    In Paul's case I'm sure he has an electronic engine and probably doesn't need the alt tach signal but it may not hurt that it is there .

I'm thinking about buying a Blue Sea ML-ACR too since my chassis batteries are not charging off shore power .  The good things you and others have reported about that system makes me feel it would be easier and better than diagnosing and repairing my present system .                             

 Here's how I feel about replacing alternators on these coaches .  I understand many people have replaced theirs with success but some have had grief .   Many mechanics ( parts changers )  don't understand or believe there is a difference in Monaco alternators .  Some parts sales people are in denial too .  So owners have used a "supposed to work" alt and the old one is now long gone .  Some mechanics have screwed up the wiring thinking don't worry I can fix it .  So I believe the safest way for the everyday guy to get back on their trip is to have it rebuilt  .

    My 2 cents 

 

    

Edited November 5, 2020 by Ray Davis

[vanwill52]

12 minutes ago, Ray Davis said:

Van , I have no personal experience with the tach and alternator issue , I was really parroting what I remember Bill D telling people many times .  It is interesting that you have a 2000 model yet your tach is driven by the tach .  Do you have a mechanical engine ?  If you do then that is the answer but with that said I see no reason why an electronic engine couldn't use the alt to drive the tach .  Am I wrong is assuming that ?  You know what they say about assuming anything .   I have always believed that mechanical engine  ( alt / tach ) electronic engine ( ecm / tach ) I think that is what Monaco did for the most part .    In Paul's case I'm sure he has an electronic engine and probably doesn't need the alt tach signal but it may not hurt that it is there .

I'm thinking about buying a Blue Sea ML-ACR too since my chassis batteries are not charging off shore power .  The good things you and others have reported about that system makes me feel it would be easier and better than diagnosing and repairing my present system .                             

 Here's how I feel about replacing alternators on these coaches .  I understand many people have replaced theirs with success but some have had grief .   Many mechanics ( parts changers )  don't understand or believe there is a difference in Monaco alternators .  Some parts sales people are in denial too .  So owners have used a "supposed to work" alt and the old one is now long gone .  Some mechanics have screwed up the wiring thinking don't worry I can fix it .  So I believe the safest way for the everyday guy to get back on their trip is to have it rebuilt  .

    My 2 cents 

 

    

Ray, my engine is an ISC-350.  I think it is the first electronically controlled engine found in our coaches.  Yes, the wiring diagram shows a "Tach Output" from the ECM, but again, I don't know where it goes.  The tach, if it is not TOTALLY driven from the alternator, at least requires that the "Tach" terminal on the alternator be properly connected.

I  hope Paul Whittle chimes in.  He converted his charging system to use the ML-ACR.  I THINK he had a BIRD system before.  I understand the basics of how the BIRD system works, but before I would spend any time troubleshooting a trouble-prone system, I would simply replace all the electronics and relays with the single ML-ACR component, whose guarantee reads, "We stand behind this product for as long as you own it."  Period.  The wiring (re-wiring) for the ML-ACR is super simple and inuitive, once you realize the ML-ACR does one and only one thing--It either COMBINES your house and engine battery banks, or it SEPARATES them.  And it does so automatically, based on what (if any) charging sources (alternator, inverter-charger, external chargin device) are present.  PLUS, the remote control switch you install in place of your BOOST switch, allows you to FORCE the ML-ACR into any state you wish--Automatic, Battery Banks Connected, Battery Banks Separated.  And lastly, the "ML" part of ML-ACR is for "magnetically latched"--it only requires milliamps to maintain it in either of its two states.

I'm sure I'm prejudiced, since I made this swap, but it replaces a system that folks have difficulty getting diagnosed and repaired with a ONE-COMPONENT device inexpensive enough (less than $200) to carry a spare.

 

I have nearly 1000 AH of (8) T-145 size batteries.  And yes, I have committed "Monaco heresy" in mixing battery brands and ages, and have had no issues in over four years, including a trip to AK from NC.  I welded a new battery pan and mounted two Group 24 12V batteries on the driver side in the rear of the engine compartment.

[Ivan K]

As far as I know, mechanical vs. electronic refers to injection and emissions management, ability to derate when there is a problem. They all have an ECU since long time ago that knows what the exact RPM is and is able to pass it on to a display through data link. It is the OEM that decides how to source it and display it and Monaco decided for us. Therefore, in my case, I have computer reading on scangauge to compare to analog reading on factory analog gauge, fed by alternator signal, if I care to do it. Two independent systems.