Alternator charge warning light and chime

[Steven P]

Today I decided to run my coach (been a month) and I fired the gennie first, then the engine.  After 10 to 15 minutes I started getting an alternator charge warning light and chime on dash.  Aladdin read bw 13.5 and 14.4 volts,  Scangauge running bw 13.6 and 14.4 volts.  If I turned on headlights, it'd stop.  If i turn off the magnum charger, it stops.  If I turn the charger on, it starts back.  Seems like it's over charging.  I have an Amp L start that I installed almost a year ago.  This issue is new.  Any ideas?  Thank you. 

[Dr4Film]

When the engine is running the charging voltage coming out of your alternator should be about 14.1-14.4, at least that is what mine is. Don't understand why you have a bigger range down in the mid 13's.

[Ivan K]

Don't know if you might have a battery isolator in the rear but if you do, I would check for 0 volts at the center post with engine off to confirm that it isn't back feeding the alternator.

[Steven P]

Thanks,  I will.  Anyone have a pic of the battery isolator?  When I installed the Amp L Start last year, we threw an engine fault which said volts too high, but never had the alt light going off.  It did it one more time this year.  Very inconsistent.  As long as I kept the battery charger off, the beeping didnt return.  I didn't have a lot of time to investigate more.  

[Ivan K]

Best I could do, don't have much light in this corner of the shop. It is the big blue finned box at the left. You may not have it since it is considered an old technology.

[Steven P]

Thanks.  I will look, but I dont think I have that one either. 

[Dr4Film]

Steven, here is a photo of my Battery Isolator Relay which is made by White-Rogers.  Some of the newer models have been using a BigBoy Relay which looks similar.

It is the big relay located in between and just below the two large Guest Battery Disconnect Switches and just above the White -Rogers Battery Cut-Off Relay (which is bypassed).

[larry.jervis@att.net]

Steven, I have had this issue s couple of times over the 15 years that I owned my 2004 Diplomat. Each time the issue was the voltage regulator in the Leece  Nevel Alternator. The last time I had this issue I changed my alternator out to Acdelco Reme , it was a direct swap and got rid of the issues with the Leece alternator. Voltage is now a continuous 14.5 at idle all the to 2200.

 

Larru

2004 Diplomat 

[Steven P]

Thank you both!  I will look further into this soon.  I'll try to get some pics of my battery bay, but it seems like it has something to do with feeding back from the battery charger with the gennie running.  Do Amp L starts go bad?  

[Dr4Film]

Steven, my OEM Lambert Battery Maintainer went bad and the Amp-L-Start was what I had put in its place. Certainly any electrical component can fail.

Here is a link to troubleshooting the Amp-L-Start - http://www.lslproducts.net/ALS_Instructs.pdf

[David White]

“Thank you both!  I will look further into this soon.  I'll try to get some pics of my battery bay, but it seems like it has something to do with feeding back from the battery charger with the gennie running.  Do Amp L starts go bad? “

Yes, Amp L Starts do go bad.  

[Steven P]

I have some updated info on my battery charging concern.  Today I changed my old BEP switches to Blue Seas switches and that went well until the house charger started charging.   Then Amp L Start started flashing red which from what I see is common if volts exceed 14.7V and it's supposed to shut off charging of the chassis batteries to protect them.  However, all batteries were measuring 14.8V w a voltmeter and I could hear them "cooking".   Inwas hooked to shore power and the engine was not running.  I checked all my settings and they seem appropriate. Talked w Scotty and decided to change the flooded setting to AGM.  This lowered the charging to 14.4V.  

Sorry for the long post.  Is it normal for the charger to charge at 14.8V?  It was in the absorb state at the time.  Since the chassis batteries continued to charge while the Amp L Start was flashing red, has its protective feature gone bad?  

Thank you, 

Steven P

[larry.jervis@att.net]

Steven,

My Magnum MS2012 (2000Watt) normally charges in Bulk and Absorption mode of 14.6 to 14.8 so the voltage you seeing seems to be correct. Now remember that every time the power is disconnected and reconnected the Magnum Inverter/Chargers starts the programmed charging cycle. The default charging cycle is 120 Minutes but can be changed through the Setup keys on the remote.  If the charge cycle was interrupted by either loss of power (turn generator off if on that power source or shore power) the charge cycle when then Magnum is powered back up will start the 120 minute charge program but the Bulk Rate charge will be less as the % charge of the batteries will be higher. This just extends the Float rate charge after the Absorption rate is complete.

As I look back on the first post photo showing the Aladdin 14.1 and  Scangauge  13.8`  Battery Charge Voltage they are .4 volts  . Now the Aladdin voltage information is coming from a different connection than the ScanGauge. I would check all the Ground connections in the dash, battery compartments, Chassis and all run panels (front and Back). I chased a issue with gauges in the dash and turned out a loose ground. After that incident I went through the entire coach and tightened every ground, even pulled most on the Chassis and cleaned the connections then put dielectric grease on the connections to make sure there was a good ground. After that exercise my issues with the dash along with correct voltage reading between the Batteries. Alternator, and ScanGauge were correct.

Note: The Charge Voltage on the Magnum remote is showing the state of the House Batteries not the Chassis Batteries as when the Generator is on the Chassis Batteries are isolated from being charged from the generator, that is why there is a difference in the dash voltage and the Magnum remote.

There is also a 'Charge Fault Relay' that is powered from Aux Terminal on the Alternator that turns the 'Alt Charge' light on the dash. The normal mode is when the Alternator's output is at normal voltage 13.8 -14.5 the Aux terminal is outputting 6 volts (that is the normal output voltage). This 6 Volt output energizes the coil in the ' Charge Fault Relay' that turns the 'Alt Charge' light on the dash off and when the engine is not running but the key is in the run position the 'Alt Charge' is Lite. In the situation that the first photo shows is the Alternator is outputting 14.1+ Voltage but the 'Alt Charger' Light is on. This means that either the Charge Fault Relay is bad (mine went bad this last summer) or the Aux output on the Alternator is Bad but I would not bet on that or the 14+ volt on the dash gauges would not be correct. Now the wire on the Aux terminal on the Alternator may have come loose or it is just the 'Charge Fault Relay' have failed.

Note: The Charge Fault Relay has a (6 Volt Coil) not a 12Volt, as the volt from the Alternator to the relay is 6Volts. This Relay is not going to be available at the most local parts houses, I will try to find the part number for the relay I purchased (purchased from a Cummins dealer as used in Diesel trucks) so to help you location a replacement. Once you find the relay just remove it and the light will turn out until you find a replacement relay, the part # and coil voltage will be marked on the top or side of the relay. The relay is a Black square plugin style relay, mine was located in the Front Run panel (Driver side) on the right side wall when looking into the bay, Yours may be located in different location so you will need to hunt for it.

Loose grounds can cause numerous issues and with the amount of bouncing and movement our coaches receiving going down the road is hard enough on the connections (just imagine putting your house on a trailer and towing a thousand miles what kind of shape it would be in) now add all the environment issues (rain, heat, cold, humidity) it is a wonder at times these coaches don't have more issues.

I have spent many days being proactive with my coach (original owner) checking and rechecking and always seem to have sometime that needs to be fixed or adjusted. I worked for years as an electrical controls design and troubling tech on high speed production equipment and loose connections were one of the most common source of failures or those phantom failures that drive everyone crazy.

Sorry for the long post but since there is not a lot of documentation around for the coaches (I was lucking mine came with a  set of electrical diagrams - these are not complete as they cover many different models but are helpful 90% of the time). If I can help you with any questions please advise.

Larry

2004 Diplomat 30'

[Steven P]

Larry,

Nice response.  Thank you. I was always wondering if my Scangauge and Aladdin should match up.  The volts are not the only reading not matching up, so I just figured there was a delay or they get their readings from a different source.  I will start checking grounds and go from there. 

Thank you again,

Steven P

[Bob Nodine]

This might work.

https://tinyurl.com/qkk95ak

 

 

Edited January 15, 2020 by Bob Nodine

[larry.jervis@att.net]

Bob,

That is the correct relay to use, when the engine is not running or the Alternator fails there is no 6 volts from the Alternator to energize the relay. When the relay is not energize the dash light and alarm sounds.

Larry 

2004 Diplomat 36'

[Larry Laursen]

When you have the unit connected to shore power the inverter/charger is charging the house batteries on a 2006 Dip and the Amp-L-Start will charge the chassis batteries from the house.  When you start the engine the engine alternator charges the chassis batteries and the house batteries are connected to the chassis by the interconnect relay (Trombetta OEM). Which is controlled by the Intellitec interconnect relay delay control device.  Thus the Amp-L-Start is no longer in play for protection.  Because the two battery banks are now hard wired together the alt fail light will be activated if the inverter/charger is doing a high voltage charge.  This is quite common and generally not a concern.  If you have Alt Fail under different conditions then other items need to be looked at.

[CJ7harv2018]

On 1/13/2020 at 5:39 PM, larry.jervis@att.net said:

Steven,

My Magnum MS2012 (2000Watt) normally charges in Bulk and Absorption mode of 14.6 to 14.8 so the voltage you seeing seems to be correct. Now remember that every time the power is disconnected and reconnected the Magnum Inverter/Chargers starts the programmed charging cycle. The default charging cycle is 120 Minutes but can be changed through the Setup keys on the remote.  If the charge cycle was interrupted by either loss of power (turn generator off if on that power source or shore power) the charge cycle when then Magnum is powered back up will start the 120 minute charge program but the Bulk Rate charge will be less as the % charge of the batteries will be higher. This just extends the Float rate charge after the Absorption rate is complete.

As I look back on the first post photo showing the Aladdin 14.1 and  Scangauge  13.8`  Battery Charge Voltage they are .4 volts  . Now the Aladdin voltage information is coming from a different connection than the ScanGauge. I would check all the Ground connections in the dash, battery compartments, Chassis and all run panels (front and Back). I chased a issue with gauges in the dash and turned out a loose ground. After that incident I went through the entire coach and tightened every ground, even pulled most on the Chassis and cleaned the connections then put dielectric grease on the connections to make sure there was a good ground. After that exercise my issues with the dash along with correct voltage reading between the Batteries. Alternator, and ScanGauge were correct.

Note: The Charge Voltage on the Magnum remote is showing the state of the House Batteries not the Chassis Batteries as when the Generator is on the Chassis Batteries are isolated from being charged from the generator, that is why there is a difference in the dash voltage and the Magnum remote.

There is also a 'Charge Fault Relay' that is powered from Aux Terminal on the Alternator that turns the 'Alt Charge' light on the dash. The normal mode is when the Alternator's output is at normal voltage 13.8 -14.5 the Aux terminal is outputting 6 volts (that is the normal output voltage). This 6 Volt output energizes the coil in the ' Charge Fault Relay' that turns the 'Alt Charge' light on the dash off and when the engine is not running but the key is in the run position the 'Alt Charge' is Lite. In the situation that the first photo shows is the Alternator is outputting 14.1+ Voltage but the 'Alt Charger' Light is on. This means that either the Charge Fault Relay is bad (mine went bad this last summer) or the Aux output on the Alternator is Bad but I would not bet on that or the 14+ volt on the dash gauges would not be correct. Now the wire on the Aux terminal on the Alternator may have come loose or it is just the 'Charge Fault Relay' have failed.

Note: The Charge Fault Relay has a (6 Volt Coil) not a 12Volt, as the volt from the Alternator to the relay is 6Volts. This Relay is not going to be available at the most local parts houses, I will try to find the part number for the relay I purchased (purchased from a Cummins dealer as used in Diesel trucks) so to help you location a replacement. Once you find the relay just remove it and the light will turn out until you find a replacement relay, the part # and coil voltage will be marked on the top or side of the relay. The relay is a Black square plugin style relay, mine was located in the Front Run panel (Driver side) on the right side wall when looking into the bay, Yours may be located in different location so you will need to hunt for it.

Loose grounds can cause numerous issues and with the amount of bouncing and movement our coaches receiving going down the road is hard enough on the connections (just imagine putting your house on a trailer and towing a thousand miles what kind of shape it would be in) now add all the environment issues (rain, heat, cold, humidity) it is a wonder at times these coaches don't have more issues.

I have spent many days being proactive with my coach (original owner) checking and rechecking and always seem to have sometime that needs to be fixed or adjusted. I worked for years as an electrical controls design and troubling tech on high speed production equipment and loose connections were one of the most common source of failures or those phantom failures that drive everyone crazy.

Sorry for the long post but since there is not a lot of documentation around for the coaches (I was lucking mine came with a  set of electrical diagrams - these are not complete as they cover many different models but are helpful 90% of the time). If I can help you with any questions please advise.

Larry

2004 Diplomat 30'

 

Hi could you please provide a picture of the relay and it’s location. I’m having the same issue.

[jacwjames]

7 hours ago, CJ7harv2018 said:

 

Hi could you please provide a picture of the relay and it’s location. I’m having the same issue.

I had 3-4 relays in my front run bay that were hanging loose attached to a wiring harness.   I peeled back the black wiring loom on each of them, the wiring has markings as to what the wire is for, I was able to find the Alt Fail Relay and others by looking at the wires and the wiring diagram I have.  Once I figured out what they were I labeled them.  I use a label maker to mark anything that isn't already marked and I take pictures of most things and put the pictures in a folder.  One of the three that are labeled was the alt fail relay. 

[tomevansfl]

I have a 2001 Diplomat.  My system is older, so it may be a little more primitive.  On my return home from a park near my house, I had the generator running so I could keep the house a/c's on. (last week was one of the hottest and most humid in history.  I noticed the Alt Charge light started flashing.  When I was stopped at a traffic light, the Alt Charge light didn't flash or come on. It was only when I was moving/accelerating. It was intermittent.  All gauges seemed to be in the normal range except the voltage gauge.  It seemed to stay just below the 14 range. The starter seemed to run a little longer than usual, but nothing that really concerned me.  I had just drained my primary fuel filter (less than a year old) and replaced my secondary fuel filter installed by Monaco on the chassis frame. So I just attributed it to the filters continuing to prime.

Above mentions the battery isolator relay.  Does this sound like the issue? Also, how would I check/test it.  Also, does any one recognize the brand? This is my battery box:

 

[Steven P]

@tomevansfl. What you may be experiencing is a pretty common issue.  Slight overcharging w the genny and engine running.  Next time, try turning your headlights off and see if the warning goes away.  If you don't usually run your genny while driving and this only happens w the genny and engine running,  that's probably it and not a concern.  Mine does it a fair amount of the time, especially when my inverter is in "bulk" charging mode. I have an Amp L Start so the chassis batteries will stay charged when on genny or shore power. Hope that makes sense. 

Otherwise, check your chassis battery voltage w the engine running and see what you have across the posts, not on the dash gauge. It's always possible for an alternator voltage regulator to go out. 

[tomevansfl]

26 minutes ago, Steven P said:

@tomevansfl. What you may be experiencing is a pretty common issue.  Slight overcharging w the genny and engine running.  Next time, try turning your headlights off and see if the warning goes away.  If you don't usually run your genny while driving and this only happens w the genny and engine running,  that's probably it and not a concern.  Mine does it a fair amount of the time, especially when my inverter is in "bulk" charging mode. I have an Amp L Start so the chassis batteries will stay charged when on genny or shore power. Hope that makes sense. 

Otherwise, check your chassis battery voltage w the engine running and see what you have across the posts, not on the dash gauge. It's always possible for an alternator voltage regulator to go out. 

Thanks, Steven.  My chassis batteries were replaced with new from Cummins last September.  I didn't have my headlights on, but I'll turn them on next time so see if there is a difference.  This was the first time I noticed it, but I think it may be the house batteries that is causing this. 

I've had my Diplomat for about 2 years.  I usually go to the storage lot the day before a trip and turn the inverter on so the residential fridge will be cold the next day when we leave, On the day of departure I usually have about 75-80% of battery level left.  My wife packs the cold stuff and we put it in the fridge when we head out.  One thing though, the last two times I did this the fridge wasn't on when we arrived to head out and was still warm inside. When I tried to restart the inverter, it would buzz and turn off. I double-checked the inverter and the fuse wasn't tripped.  This leads me to believe the house batteries are going.  They were the batteries in the RV when we bought it.  I think the date on the batteries is 2017 so that is most likely the problems with the house batteries. The next chore is to inspect them thoroughly. When we travel I always have the generator on so the fridge will be on and we can use the house A/C's.  We live in central Florida, so A/C is a must!

Fortunately, the fridge cools down quickly and by the time we arrive the fridge is cold enough to transfer food from the cooler.

Again, thanks for the info. I'll be checking those potential issues over the next two weeks as we get ready for a week-long trip to Ft. DeSoto Park in Clearwater, FL.

 

[Steven P]

You're welcome and you may be on the right track if the house batteries are failing and some charging issues are happening and spilling over to the chassis batteries. Safe travels. 

[a4epilot]

There's nothing wrong. As long as you have shore power connected and the battery charger on, it is supplying a higher voltage than the alternator output voltage, therefore, the alternator senses there is no load connected to it so it does not output anything, therefore, the alt light comes on. If you simply turn off the battery charger, then the alt light will not come on as it sees the 12VDC loads and outputs. 

Happens to me every time if I do as you have. The easiest is to turn off the charger before starting the engine, however, don't forget to turn it on after the engine is shut down.

Regarding running the engine without driving. That's the wrong thing to do. What I'm about to say applies to any internal combustion engine including your diesel. I don't have time to get into the damage that you are doing to the engine but you can do some research to find out. Don't know if Cummins still has the tech phone number but if they do, call and confirm what I'm saying. The only time you should start the engine is if you're going to drive it for at least 20+ miles to bring everything to operating temperature in part to eliminate the harmful contaminates produced at low RPM's by never getting up to operating temps. Idling the engine does damage at any time. Operators who think they have to warm up a diesel are wrong. Ask and they cannot tell you why they do it other than that's what the big trucks do. In fact, that's not what they do. That's what the uninformed think is happening. You have two additional higher RPM idle settings available by using the cruise control switch. If you've been driving and are going to stop for a short time, do not keep the engine at idle. Shut it down if it's going to be for more than a minute or so. OR, if you need to keep it running for some reason, then select the lower of the 2 higher idles available. Allowing the engine to idle at the normal low RPM can overheat the injector pump, the injectors and create harmful deposits in the oil.

As confirmed with Commins engineers, I do not move all winter in AZ & never run the engine for 6-7 months. That's not the best thing to do for many reasons I won't get into now. However, that is better than running the engine without driving. That is the takeaway.

Final point. When ready to drive, the best option is to confirm oil pressure and then drive off at a moderate speed regardless of the outside temps. Yes, even in very cold weather. That's what one should do with a car as well.  When departing an RV park, it's not possible to start the engine and then drive off because there are things that need to be done as you're going through your departure procedure. Keep in mind, idling is harmful so if after you start and move a little and then need to do some additional tasks outside, if it's going to be for more than a short time, shut it down and restart later.

There may be some who will respond with negative comments about what I have written. If so, and even if they don't because you don't know me or my qualifications, go online, do some research and then proceed knowing you have the proper information.

Gary K

 

[tomevansfl]

Thanks Gary. Sorry if I misled. My generator was on while driving but not at idle at any time except while waiting for a traffic signal change. That was the only time the alt charge light did not flash at irregular intervals, it only flashed while going down the road. I’m glad it doesn’t mean there is something “broken” in my electrical system. 
 

My charger (Xantrex) says float charging. It is when I use the inverter to supply the residential refrigerator that no power is detected. The Xantrex buzzes or clicks when switched on and then switches off. I am interpreting that to mean my house batteries are at the end of their service life. The only time I have used the house batteries has been the 24 or so hours before leaving to pre-cool the refrigerator for the trip. The last two times we just left the perishables in the ice chest until we were on generator for the trip. Our fridge cools down very quickly so that hasn’t been an issue. We are going on a week-long trip in two weeks.
 

My wife has scoped out the grocery stores near our destination so we decided to run the generator to operate the house air conditioners on the 2-1/2 hour drive and let the fridge run for that time so it will be cold when we arrive at the grocery store near our campground. 
 

When I replace my house batteries I plan to replace them with lithium and add solar and upgrade the charger/inverter to work with the lithium.  Until then, I’ll wait until the fridge has run on generator or shore power long enough to reach operating temp before adding perishable food to it. 
 

Thanks again for the help.