Preventing DUVAC alternator problems

[Cubflyer]

Grampy OG-Ken,

If you have not figured it out already..... a "step drill" bit does a great job of opening up the large but not large enough wire terminals so they fit the ML-ACR  terminal posts.

Ken 

[Grampy OG]

21 hours ago, Cubflyer said:

Grampy OG-Ken,

If you have not figured it out already..... a "step drill" bit does a great job of opening up the large but not large enough wire terminals so they fit the ML-ACR  terminal posts.

Ken 

Yes, thank you for the hint. It worked well and NO GRABBING by the bit. Worked out great.

Thank you

[jacwjames]

6 minutes ago, mike_fluharty said:

I have been following this topic for awhile and ordered an ML-ACR yesterday.  One question I have is where is alternator (DUVAC) getting its battery voltage information from, it appears that all the wires that were going to the ssi are being moved to the ML-ACR so where is the alternator battery sense wire coming undone?

Thanks,

Mike Fluharty

2003 Safari Zanzibar

ISL 370

On my coach there is a separate circuit for the DUVAC circuit, I have a fuse in the passenger side rear electrical compartment with the circuit hooked to the battery. 

[ok-rver]

2004 HR ISC with LN "DUVAC" alternator. There are several connectors in the battery compartment and one is labeled DUVAC. The MH has a battery bank combiner but it is not like the ones I am seeing in these posts. It is a simple White-Rogers/RBM relay. Purple and white wires connected to the coil terminals. Relay posts connected to both battery banks, one cable is much smaller. Looks to be the original installation. I do not have the finned component shown in the OP pictures. I am not getting charging between the battery banks. The dash combine switch works correctly as I use it when we have been on shore power for some time to boast the start battery.  I have jumped 12v to the coil to close relay and see 70 amps going from house to start when on shore power. Was the big boy an option or am I missing something that is not in the battery compartment?

I looked at the ML-ACR specs. Does the ACR charge both directions? I would be good if when on shore power the chassis batteries were charged.

bright red plastic in picture is lead to my volt meter 

[waterskier_1]

50 minutes ago, ok-rver said:

2004 HR ISC with LN "DUVAC" alternator. There are several connectors in the battery compartment and one is labeled DUVAC. The MH has a battery bank combiner but it is not like the ones I am seeing in these posts. It is a simple White-Rogers/RBM relay. Purple and white wires connected to the coil terminals. Relay posts connected to both battery banks, one cable is much smaller. Looks to be the original installation. I do not have the finned component shown in the OP pictures. I am not getting charging between the battery banks. The dash combine switch works correctly as I use it when we have been on shore power for some time to boast the start battery.  I have jumped 12v to the coil to close relay and see 70 amps going from house to start when on shore power. Was the big boy an option or am I missing something that is not in the battery compartment?

I looked at the ML-ACR specs. Does the ACR charge both directions? I would be good if when on shore power the chassis batteries were charged.

bright red plastic in picture is lead to my volt meter 

It appears you have an IRD (Isolator Relay Delay) which only allow for charging of both battery banks from the alternator.  You would need a BIRD K Bidirectional IRD) to charge from the shore power inverter/ charger to both battery banks

The wire marker DUVAC is the sense wire for the alternator and should be connected to tuff Chassis battery positive terminal. 

[vanwill52]

3 hours ago, ok-rver said:

2004 HR ISC with LN "DUVAC" alternator. There are several connectors in the battery compartment and one is labeled DUVAC. The MH has a battery bank combiner but it is not like the ones I am seeing in these posts. It is a simple White-Rogers/RBM relay. Purple and white wires connected to the coil terminals. Relay posts connected to both battery banks, one cable is much smaller. Looks to be the original installation. I do not have the finned component shown in the OP pictures. I am not getting charging between the battery banks. The dash combine switch works correctly as I use it when we have been on shore power for some time to boast the start battery.  I have jumped 12v to the coil to close relay and see 70 amps going from house to start when on shore power. Was the big boy an option or am I missing something that is not in the battery compartment?

I looked at the ML-ACR specs. Does the ACR charge both directions? I would be good if when on shore power the chassis batteries were charged.

bright red plastic in picture is lead to my volt meter 

Mike, as Rick said, it appears the relay you show connects the two battery banks only when the alternator (engine) is running.  I'm not familiar with the details of the wiring on your coach, so the one thing that I don't understand is that there are two different sized large cables attached to the main terminals of the contactor. 

Yes, the ML-ACR is bi-directional.  Any time a charging voltage is detected from ANY source, the ML-ACR detects it and connects both battery banks together to charge them at once.  When the charging voltage disappears, the ML-ACR disconnects the two battery banks, preserving the charge on the chassis battery, even as the coach batteries are being depleted.  It also accomplishes the Battery Boost function, so that no Big Boy is needed.

Each ML-ACR installation is only slightly different, depending on how the coach was originally wired.  The bottom line is that you connect the alternator output directly to the chassis battery, then connect another heavy cable from the positive terminal of the CHASSIS battery to one large post of the ML-ACR, and connect another heavy cable from the positive terminal of the HOUSE batteries to the other large post of the ML-ACR.  Attach the two (black and red?) small wires from the ML-ACR to ground and an "always on" positive supply.  The ML-ACR then takes over the function of both the IRD and the Battery Boost contactor, and both original devices can be removed.

Bear in mind as you wire it that the ML-ACR does only ONE thing--it either connects the positive terminal of both battery banks, or disconnects them, based on whether any charging source is detected.

[Dr4Film]

As Van stated  once you remove the White- Rogers Battery Isolator Relay and install the ML-ACR in the same place you don't need your IRD or a BIRD or any other device.

The ML-ACR detects the charging source, Shore, Generator or Alternator and will connect the two battery banks together to keep those batteries fully charged.

[jimc99999]

I'm now replacing my 24 year old electronics in my 97 Windsor with the ML-ACR. Thanks for the tip on using a step drill bit, it works great to enlarge the holes in the wires. 

I do have a couple questions. Is it necessary to set up the start isolation if you are starting the coach while plugged into shore power or with the generator running?

Also, should the second isolation circuit be configured to prevent connecting the sides while both the alternator and the generator are charging (I.e. running the generator while driving)? Or does that not really matter too much?

[pwhittle]

I did not attach any of the isolator inputs.

On boats this is often used to protect the electronics when cranking the engine. There are not as many sensitive electronics on a motorhome

Paul

[jimc99999]

I haven't wired up the remote yet, but here's a before/after. The battery aux relay showed continuity and gave a big clunk when the "aux boost" dash button was pressed, but it couldn't flow much current. When the house batteries got too low to start the generator I had to use jumper cables from the chassis to house batteries because the aux boost couldn't do it.

And even though the green light is showing on the trickle charger it had also stopped charging recently. 

House batteries are AGM, chassis batteries are sealed lead acid. Now that the inverter/charger can charge them at much higher current, should I set the inverter to AGM or flooded battery settings? Or does that really matter much?

 

[Tazmanian Martje]

Are any of you Monaco Gurus in the Panhandle of Florida?  We lot our Duvac in Christiansburg Va just before Thanksgiving. Spent a 19 degree night in the rest area with NO heat or anything..  they replaced the alternator(minor fiasco) hooking up new from duvac wires.  Researched and found this thread.  Am ordering the ML-ACR today.

I have been piecing together little symptoms that tell me either the lambert or ssi is bad.  Oh and first thing replaced was the BigBoy.  slowly am learning electrical, what a challenge.

We have a 2003 Monaco Signature.  1st time RV owners.  I want to find knowledgeable work for this.  I have repaired the AC units and refridgerator myself.  but am not confident to do this changeover.

Anyone willing to help a gal out?

[waterskier_1]

2 hours ago, Tazmanian Martje said:

Are any of you Monaco Gurus in the Panhandle of Florida?  We lot our Duvac in Christiansburg Va just before Thanksgiving. Spent a 19 degree night in the rest area with NO heat or anything..  they replaced the alternator(minor fiasco) hooking up new from duvac wires.  Researched and found this thread.  Am ordering the ML-ACR today.

I have been piecing together little symptoms that tell me either the lambert or ssi is bad.  Oh and first thing replaced was the BigBoy.  slowly am learning electrical, what a challenge.

We have a 2003 Monaco Signature.  1st time RV owners.  I want to find knowledgeable work for this.  I have repaired the AC units and refridgerator myself.  but am not confident to do this changeover.

Anyone willing to help a gal out?

You have some conflicting info in your post.  You either have an SSI (Solid State Isolator)  OR  a Big Boy,  not both that I've ever seen.  

It would be helpful if you describe what the symptoms were that caused you to replace the alternator, and what problems you are currently having. From what you describe, I'm not sure if you have a chassis battery/ charging/  system problem, a house battery/ charging/ system problem, both, or neither.  The SSI's purpose is to allow the main engine alternator to charge both the chassis & the house batteries.  On the other hand, the Lambert's purpose is to allow charging the chassis batteries from shore/ generator power.  The house batteries are designed to charge from shore/ generator power without ant additional devices (SSI, Lambert, Big Boy, etc.).  So, you should have been able to start the generator and keep the house batteries charged and had full heating.   

Please clarify the situation, and I'm sure we can get it sorted. 

  - Rick N 

[vanwill52]

Rick, my 2000 Dynasty might be an exception, but before I replaced the SSI and Lambert with the ML-ACR, it ALSO had a Big Boy.  In my case, it was used only as a battery boost solenoid.  All three items were replaced with the ML-ACR, and although I still have a functioning DUVAC alternator, I could now replace it with any of a dozen different generic HD alternators.  IMHO, once someone has replaced a DUVAC alternator with a non-exact replacement and has trouble, going the ML-ACR route is much simpler than trying to diagnose and repair whatever was mis-wired.  What do you think?

[Guest Ray Davis]

44 minutes ago, Tazmanian Martje said:

Spent a 19 degree night in the rest area with NO heat or anything.

Couldn't you run the generator?   Actually, people drive using the generator when their alternator fails.   You do need to make sure the alternator turns freely though so the water pump can still operate.

[waterskier_1]

2 hours ago, vanwill52 said:

Rick, my 2000 Dynasty might be an exception, but before I replaced the SSI and Lambert with the ML-ACR, it ALSO had a Big Boy.  In my case, it was used only as a battery boost solenoid.  All three items were replaced with the ML-ACR, and although I still have a functioning DUVAC alternator, I could now replace it with any of a dozen different generic HD alternators.  IMHO, once someone has replaced a DUVAC alternator with a non-exact replacement and has trouble, going the ML-ACR route is much simpler than trying to diagnose and repair whatever was mis-wired.  What do you think?

Van, you right, there is a relay that for the Battery Boost Function.  I forgot about it because it isn't part of the charging/isolator circuitry.  So, it is possible Margje did replace that relay, but it wouldn't have helped the charging problem, which I'm still not clear what exactly it is.  

Thanks for keeping me straight!

  -Rick N.

[Tazmanian Martje]

Are any of you Monaco Gurus in the Panhandle of Florida?  We lot our Duvac in Christiansburg Va just before Thanksgiving. Spent a 19 degree night in the rest area with NO heat or anything..  they replaced the alternator(minor fiasco) hooking up new from duvac wires.  Researched and found this thread.  Am ordering the ML-ACR today.

I have been piecing together little symptoms that tell me either the lambert or ssi is bad.  Oh and first thing replaced was the BigBoy.  slowly am learning electrical, what a challenge.

We have a 2003 Monaco Signature.  1st time RV owners.  I want to find knowledgeable work for this.  I have repaired the AC units and refridgerator myself.  but am not confident to do this changeover.

Anyone willing to help a gal out?

 

the roadside assistance couldn't replace the dead batteries that night. they did get us jumped, but engine only ran for a short time.  Generator could not be started, not enough juice, the batteries they had on hand had screw connectors not posts.  The generator wouldn't start. not enough battery.  when we first bought it last january the house batteries wouldn't stay charged the big boy was bad.  we needed to run the aquahot to keep it from freezing.  Ned wired a 50amp service from the house to the rv so we had aquahot.  the previous owner had a trickle charger hooked up to the chassis batteries.  we needed to  use a charger for the batteries to keep charged.  Even with shore power they won't stay charged.  

when we left to come to Florida I had no heat in the coach,  then the tranny started shifting weird.  I immediately pulled over in the rest area.  the batteries were dead.  ended up waiting till morning and I took the car and bought 2 new batteries, and then drove to O'riellys and they tested the alternator, bad.  so drove back to Christiansburg to total car care roadside and they found an alternator via the vin number.  hooked it up wrong.  no heat, no electricity.  they finally got it right, but chassis batteries won't stay charged. 

[Guest Ray Davis]

Weird acting tranny was probably due to the battery voltage dropping so low.

You should have started the generator while roadside assist was still there with their boost.

I keep a 20 ft set of jumper cables on board.  With those you could have started the generator using your toad.                                                                                                                           

The gen should eventually charge all of the batteries.                                                             

Could have kept you warm too.

Are you guys in a RV park now?  IMHO that's where you should be until you can get your elect sorted out.  There you'll be plugged into shore power and your onboard charger should then be able to charge the batteries.  If that's not happening, you can get a charger and charge them yourself.  I keep a charger in the coach just in case.   It's possible that when the alternator went bad that your chassis batteries got very low, and you have never been able to get them charged up enough to start the engines.

I'm in Tx so I can't help except on here.  A mobile RV tech might help though.

I would first see if the batteries are good.  If the batteries are toast, ( completely shot ) then no amount of charging will  fix the problem.  Interstate battery dealers are really helpful checking batteries.  They may even bring them out and install. 

IMPORTANT!!!    Before disconnecting any battery cables take really good pictures, even if someone else is doing the work.   It looks so simple but can get very confusing.

Then I would see if the batteries are being charged, if not, then find why not.

Edited January 6, 2022 by Ray Davis

[StellaTariche]

“Weird acting tranny…”

are we still allowed to say that phrase these days? 
 :)

 

[vanwill52]

4 hours ago, StellaTariche said:

“Weird acting tranny…”

are we still allowed to say that phrase these days? 
 🙂

 

ROTFLMAO !!  Good one, John!

[dl_racing427]

On 1/7/2022 at 10:07 AM, StellaTariche said:

“Weird acting tranny…”

are we still allowed to say that phrase these days? 
 🙂

 

Aren't ALL tranny's weird???  🤣

[Tazmanian Martje]

On 1/6/2022 at 4:11 PM, Ray Davis said:

Weird acting tranny was probably due to the battery voltage dropping so low.

You should have started the generator while roadside assist was still there with their boost.

I keep a 20 ft set of jumper cables on board.  With those you could have started the generator using your toad.                                                                                                                           

The gen should eventually charge all of the batteries.                                                             

Could have kept you warm too.

Are you guys in a RV park now?  IMHO that's where you should be until you can get your elect sorted out.  There you'll be plugged into shore power and your onboard charger should then be able to charge the batteries.  If that's not happening, you can get a charger and charge them yourself.  I keep a charger in the coach just in case.   It's possible that when the alternator went bad that your chassis batteries got very low, and you have never been able to get them charged up enough to start the engines.

I'm in Tx so I can't help except on here.  A mobile RV tech might help though.

I would first see if the batteries are good.  If the batteries are toast, ( completely shot ) then no amount of charging will  fix the problem.  Interstate battery dealers are really helpful checking batteries.  They may even bring them out and install. 

IMPORTANT!!!    Before disconnecting any battery cables take really good pictures, even if someone else is doing the work.   It looks so simple but can get very confusing.

Then I would see if the batteries are being charged, if not, then find why not.

TY Ray we are at my sisters hunt camp and have shore power. a winter set up for us.  just sick the brand new batteries are dead. so I know we have to reconfigure to get these charging properly.

[Tazmanian Martje]

OK guys, we have a new leece-Neville alternator.  Don't judge, but we were too cold to think straight and did not take a picture of the leece-Neville alternator before they removed it and replaced with a non duvac alternator.  Kicking myself. 

Anyways is there anyone out there that has a 2003 Signature with a 500hp cummins and a big boy isolator?  If so, would you please take a picture of the Alternator connections and of the batteries.  next to our chassis batteries are 2 small black wires that are just dangling.  I would like to know where exactly they go.

[Bjohnsonmn]

Making sure I have interpreted all of this discussion correctly:

If I've removed the Battery connect solenoid that bridges the house and chassis batteries and am going to a DC-DC charging system, I can replace my Lecee DUVAC alternator with a standard alternator that any Cummins powered vehicle would use, greatly simplifying my life 

If so, any recently purchased alternators people are having luck with? The positive battery post on my Lecee is wiggle loose now and not charging, so something needs to be done.

[waterskier_1]

7 hours ago, Bjohnsonmn said:

Making sure I have interpreted all of this discussion correctly:

If I've removed the Battery connect solenoid that bridges the house and chassis batteries and am going to a DC-DC charging system, I can replace my Lecee DUVAC alternator with a standard alternator that any Cummins powered vehicle would use, greatly simplifying my life 

If so, any recently purchased alternators people are having luck with? The positive battery post on my Lecee is wiggle loose now and not charging, so something needs to be done.

While a DUVAC alternator may not be required for voltage sense and regulation, you will still need an alternator which has AC taps which drive both the tach (on your coach) and the ALT-FAIL circuitry for warning of a failing alternator. 

  - Rick N 

[Frank Bergamo]

If it were me, I would rebuild the original one. JMHO.