Alternators

[merle&louise]

Can anyone tell me how to check to see if my alternator is working? I'm not sure what size it is (no markings that I can read). The engine is a 1999~ series 60 DDEC.

I had a tech check it and what he did was to put a volt meter on it first to test the battery. Then he put an amp meter clamp around the red cable as I ran the engine; it read 20 amps. He said that the alternator was working properly.

My volt meter on the dash shows 12V when driving @ 65 mph, but when I start the generator it will run up to 13.5+. Why?:confused:

[Lee Bornstein]

Tuga:

If I understand your question correctly, Voltmeter/Ammeter test on Alternator shows 20A. This means battery/batteries are nearly charged and Alternator load is 12v X 20a = 240 Watts (not that much).

Not familiar with the setup on your Newell but I'll tell you about my Liberty. The big alternator on my 97 Prevost (Detroit 60) is rated at 270A output or 12 X 270 = 3240 Watts that charges my House Batteries and runs the huge DC motors required for my Prevost Over the Road Heat/AC system. If I have a 20A load... that's less than 10% of the total capacity of the alternator.

I also have a 24V alternator used for charging Engine Staring Batteries.
On my Dashboard I have three (3) meters used to monitor the electrical system.
One meter shows both Battery Voltage and Amperage on the Engine Starting System. (Typically 26 -27 Volts)
Another meter shows both Battery Voltage and Amperage on the House Battery System.
The third gauge is a Volt Meter showing voltage on the Diesel Generator Starting Battery. If the Generator is running, this shows about 13.4 Volts.

Could it be you're looking at the Diesel Generator Starting Battery Voltage when you refer to 13.5+ Volts?

Hope this sheds some light on your situation..

Lee

[MangoMike]

Tuga / Lee,

I could be wrong here but...

It's my understanding, from messin' w/ restaurant stuff, that a clamp meter displaying amps only shows what is being drawn from the system not total charging capacity.

One of the brains needs to step in here.

Mike

[garyde]

Yes Mike that is correct. Lee was saying there was not much amperage flowing to the batteries because they were full. Current (Amperage) flows at the rate of demand. Gary

[Jon Wehrenberg]

Maybe I'm being simplistic, but I check alternator output by verifying output voltage is around 27 volts. The easiest place for me to check it is at the bus battery bank.

If the voltage is less than that the alternator is not doing its job.

As was expressed earlier, the amperage is only an indicator of how depleted the batteries are or how big the load is on the batteries.

The alternator output is going to be higher than the nominal battery voltage because it is just like the situation when you try to fill the bus tires. You can eventually fill a tire to 110 PSI if the compressor only maintains 110 PSI, but it will take forever, so you use a compressor that can maintain a higher pressure, such as 140 PSI.

Think of batteries as a tire and the voltage as pressure. If you want to top off batteries that need 25.6 volts you need an input voltage of some value greater than that such as 27 volts. Amperage would be akin to the volume of air, so as the batteries are loaded or are depleted, you want to deliver more volume so you do not go into a discharge condition.

[Lee Bornstein]

The original questiob posted by Tuga was:

"My volt meter on the dash shows 12V when driving @ 65 mph, but when I start the generator it will run up to 13.5+. Why?"

Answer: The Volt Meter on the dash he's referring to is the one that monitors Generator Starting Battery Voltage. It will show 12V when Generator is off and 13.5V when generator is running and alternator on generator is charging.

Would you all agree with me on this?

Lee Bornstein BSEE, MSEE, POG, AKC and more.

[MangoMike]

Lee,
Not that I want to speak for TUGA, but we all love to spew forth.

I still thinks he's referring to the voltage on the house batteries that should be charging by the engine/house alternator as he's motoring down the road, but doesn't. But will charge when he fires up the generator then will charge the house batteries via the inverter/charger combo.

Mike

[Lee Bornstein]

Guess we'll have to wait for Tuga to come back with more detail.

Can't wait .... I'm ready to spew forth now!

Lee

[merle&louise]

Lee & Mike:

The volt meter on my dash shows voltage of the engine/generator batteries.

The Link 2000 next to my microwave shows the voltage of the house batteries; bank 1 & bank 2. I THINK that the alternator will charge the house batteries AFTER it charges the engine/generator batteries. The problem is the alternator is not charging the engine batteries; therefore, it can not charge the house batteries.

I do not have a meter on my dash that shows house battery voltage.

The volt meter on my dash reads 12 v when the generator is not running.
It kicks up to 13.5 as soon as I start the generator. This would indicate to me that the alternator is not charging the engine/generator batteries.
A CHECK ENGINE light comes on and off when the voltage of the engine/generator batteries drops to about 11 volts.

When I start the generator; no more CHECK ENGINE light.

My knowledge in this area is limited, so please bear with me.:o

[Jon Wehrenberg]

Now it is getting clearer. What you have to do Tuga is determine why your engine driven alternator is not charging. These coaches are all different even among converters so every coach has to be examined based on its equipment. My bus has a single alternator that charges the house and the bus. Mango has a coach also by Liberty, but he has a house alternator and a bus alternator.

It sounds like you have a single alternator for both the house and bus. It could be a failed alternator, a bad or broken belt, a failed voltage regulator, or something as simple as a broken field wire if you have an external regulator.

If you are uncomfortable playing with this type of a problem just get a shop that is good at dealing with alternators and regulators. They will know in a few minutes where the problem exists.

Before you spend any money you may just want to check for broken wires or terminals at the alternator or regulator. Make sure the belts are OK, and if you want to go a little further without running the engine, just make sure there is continuity between the field wire at the regulator, and where it attaches to the alternator.

If you want to determine if it is an alternator problem or regulator problem, jump from the 12V positive (such as at a battery) to the field terminal on the regulator. Have your voltmeter hooked up to the alternator output. and the engine running. If the alternator is OK the voltage will go way past 12 volts because now it is unregulated, and the problem is the regulator. You want to be prepared to pull the jumper off right away so you do not do any over voltage damage.

If there is no output charging voltage from the alternator, the problem lies with the alternator. They can be rebuilt and usually the cost is pretty cheap compared to the cost of a new one.

[MangoMike]

Lee,
Just want to let you know that I was referring to myself as "spewing forth" and not anyone else... Well sometimes Lew.

Tuga,
Sounds like Jon has a good plan outlined for you. Best advice is a good alternator shop as going to see anyone will probably cost you some major LewBucks. But w/ 250k miles under your belt you've "been there, done that".

Mike

[Lee Bornstein]

Tuga:
Going back to your original post, looks like all is well with your alternator if you're showing 20A charging current when "Engine is Running".

Dash Voltmeter showing 13.5V when generator is running is also normal.
12V reading without generator running is normal as well. You most likely have a separate battery for starting Generator.

Info you get from the Link 2000 does not apply to charging house batteries from engine.

Link 2000 displays house battery charging current when either plugged in to shore power or Generator running. Remember, the Inverter is also a battery charger. When plugged in to shore power it charges batteries and passes 120V through to your appliances. When unplugged from shore power it converts battery 12 V to 120V for appliances.

Are you having any specific electrical problems or just curious?

Neighbor here in resort has a recent Newell - I'll go over and have a peek at his tonite if he's home.

Lee

[merle&louise]

Lee:

I am having a specific electrical problem; my laptop battery runs down and turns the computer off when it should be charging. I have it plugged into the cigarette lighter socket. Also, when I run with my lights on, the volt meter on the dash will drop to 11 volts after a few hours. Then when I start the generator the volt meter shows 13.5v and the computer battery starts charging up.

Mike:

I think that my Aqua Hot smoke is being caused by low voltage. I tested voltage at the burner's control unit and it was 12V. The manual stated that it sould be within .5v of the system voltage (13.3v according to Link 2000).

Jon:

I do have only one alternator for the house & the bus. I just changed the belt 2 weeks ago. Tomorrow I will check for broken wires, and I will attempt the continuity test(assuming I can find the field wire at the regulator). I don't want to do the jumper test, I don't think that I can pull that off yet.

If nothing is found from this, I'll just bring it to Gulf South Armature and let them find it.

We are leaving Thursday for the LSU vs Tenn game in Knoxville, so I will just wait until we return to have the alternator checked at Gulf South Armature.
I'll post the findings as soon as I can next week

It sure is fun learning about this stuff; I am very thankful to all of you for trying to help me. I'm going to try to do more of my own maintenance.

What a great forum!

Thanks guys!:) :)

[Jeff Bayley]

Tuga-

I'm a relative novice myself having only owned these buses for 2.5 years however I can point you in the right direction on one of your issues. You are on the right trail on your Aqua Hot problem as it relates to low voltage. I had my Aqua Hot "tuned up" by a guy in Florida that knew these systems backwards and forward and he said that running the Aqua Hot on low house batteries is a no no and leads to faulty performance. I can't quote you chapter and verse exactly why it faults but I think the portion of the sytem that fires it up got clogged as needed to be replaced as a result of the low voltage. I checked for his contact info and can't find it off hand. At least this can help you start asking specific questions regarding to same and avoid the systems performance eroding hence forward after you get it back on line. I'm certain that some of the other members like Jon or Harry can pick up where I leave off as to the inter workings that I think are affected by the low voltage. These systems are not a "set it and foret it" type of deal and I think they require annual maintainence.

[MangoMike]

Tuga,

Let's say that it is a voltage issue (perhaps tied into your current alternator problems). But if you fire up your generator you're getting proper voltage to your bus systems. Have you tried running the generator and the aqua hot giving it the proper voltage and seeing if that solves the smoke problem?

Keep us posted.

Mike

[garyde]

Hi Tuga. I wonder if you have a wiring diagram of your systems as it relates to charging batteries by your Generator. It seems odd that your voltmeter would be up @ 13.5 when your Generator is running. On my Lexa the Generator , thru the inverters ,would charge the House batteries first and then trickle charge the Chasis Batteries second.
I am wondering how fast your guage reads 13.5 after you turn on the Generator and if your House batteries are already on 'float'.
This is all to say your Alternator may be ok, your guage is seeing the cross current voltage.
I just read your next post and I believe you have a short in your system somewhere draining your batteries. This would explain your low voltage while the engine is running if the alternator is ok. It may also be one or several of the batteries are no good. Gary

[Jon Wehrenberg]

Gary,

I think you are dealing with apples and oranges.

Our coach batteries receive a charge from two sources. The bus alternator is one of those sources, and it sounds like that charging system is not working.

An alternative charging source is via AC electric power from the generator or shore power, through the battery charging circuits in the inverters. That system is working on Tuga's coach.

[merle&louise]

Mango:

Bingo! I ran the generator and NO SMOKE!

The house batteries showed 13.3v (both banks of batteries)
The Aqua Hot & the generator both exhaust thru the roof on my coach.

The engine/generator batteries showed 13.5v on the dash volt meter.

Jon:

I think you're correct; it is an alternator related problem. Hopefully, it is just a voltage regulator or a broken wire. With my luck, it will be the alternator!

Gary:

My alternator system charges the engine/generator batteries first and then once they are charged, it begins charging the house batteries. The opposite of your Lexa system.

The voltmeter on the dash comes up to 13.5v about 3 minutes after I start the generator. I believe that Jon is correct; it is the alternator. I changed all 8 batteries in January 2006 (6 AGM Lifeline 8Ds for the house & 2 wet cell batteries for the engine/generator) so I don't think that it is the batteries. I checked the water in the wet cell batteries - all o.k. I am going to have the alternator checked by a repair shop first, then if it is good I will load test the batteries. Reason: after I have plugged into shore power or ran the generator the engine/generator batteries show higher voltage.

Thanks for the input guys!:)

[MangoMike]

Tuga,

Man this is great. I'm always excited when we start solving some bus problems. Plus I've learned something new here as I really didn't think that minor drop in voltage would have an affect on the aqua-hot. Good to know for future guys.

Mike

[Jon Wehrenberg]

Tuga,

It is highly probable that your coach may be set up to charge your bus and house batteries at different voltages. I'm not sure of how Newell set up your systems, but it is possible the flooded wet cell batteries for the coach will get a higher voltage charge, than AGM house batteries for example. I am not saying that is how you are set up, but I would expect that if you have two different types of batteries you would have to have charging profiles appropriate to the battery type.

[MangoMike]

Tuga,

It's apparent that the easy answer is to get a Prevo - put Karen online.

Mango

[merle&louise]

Mango:

Can you give me the phone number for Liberty?

[merle&louise]

Jon:

I think that you're right; I will check with Newell when I get back from the LSU vs Tenn game.

Thanks for everything.

[Jon Wehrenberg]

800-554-9877.

They have a bunch of coaches on their web site to choose from, all with working alternators.

[merle&louise]

MM:

Aqua Hot is working perfectly; we tested it out this past weekend in Knoxville at the LSU v Tenn game. It was 39* Friday night and the inside of the coach was very warm & comfortable. Also, the hot water never ran out!

Being in Knoxville, I had to drive to Jon's house to see that DRVIEWAY! If any of you guys are ever close to Knoxville be sure to see the 8th wonder of the world. It's like driving up to Pike's Peak. I can't believe that he BACKS UP the hill and into his barn ( and yes he showed me the PIT). It's awesome, I want one.

I am going to pull the alternator off tomorrow morning and have it tested.

I'll report on it later during the week when it has been repaired.

Thanks again for all of the help.

[garyde]

Hi Jon. I have a steep driveway as well coming off the street. My front barely misses the ground backing in. How steep is your driveway. Any Pictures?

[rfoster]

Tuga: So you've been to the Mountain, Jon's Mountain. I Don't think he and Di will ever be affected by a flood; do you? Nice, very Nice.

East Tennessee - Americas best kept secret - what did you think? LSU did their thing in the last few seconds:confused: . good game, - GO VOLS!

[merle&louise]

Roger, Roger!

You have a fabulous home town; Knoxville is BEAUTIFUL! Karen & I drove around the city; ate at Calhoun's on the River, and got lost about 5 times. But we had a blast. The Tenn fans were the greatest; friendly and cordial.

The area that Jon & Di live in along the Holston River is gorgeous. The rolling hills and fall colors were magnificent. It was great football weather and it was a very close game; this Ragin' Cajun couldn't ask for more.

Before I die, I would like to see Jon back that Liberty UP THE MOUNTAIN and into the barn! Man, I just can't get over that. Gary said he also has a steep driveway. Guess I'm just accustomed to flat land.

[MangoMike]

I drove down that driveway, but didn't have the gonads to drive up. I was cryin' like a girl. (sorry Karen).

MM

[truk4u]

Did it look something like this? This was my previous drive, restricted to only 36 footers, that's why I build a new one.;)

439

440

Opps, gotta guit, thread creep!:mad:

[Jon Wehrenberg]

This is the driveway. If the bus did not have the ability to raise and lower it when and where necessary it would not make it into the garage.

[Jon Wehrenberg]

I forgot to mention, in that picture the bus is raised fully in the front so the belly will not drag. The reason you cannot see more of the driveway is it is curving quickly downhill.

As Mango will attest, when you pull out of the garage, the drop off is so steep you cannot see the driveway until the bus starts to point downhill. That feature alone makes a night time departure for first time passengers a real treat because all they see is a black hole and the tops of trees at the far end of the driveway, which also has a sharp kink in it down the bottom.

When I come up in the cars, I am pointing uphill, and I cannot see the garage floor until I start into the garage. I am waiting for the first day when I run over something on the floor because I cannot see it.

[Kevin Erion]

Jon, Is that a Newell leaving the pit?
Kevin

[Jon Wehrenberg]

It's a Newell that we cannot get to fit in the garage. It is heading for the FMCA show in Charlotte. They were very good to see if I could get one in the garage. I can't.

I can get a new XL, with the awning kit, rear spoiler and the satellite dish in the rear. It takes a little messing around, but it fits.

[lewpopp]

I hope I don't have nightmares tonite over that hill. That is scary.

Lew

[merle&louise]

I got the alternator back from the repair shop today; they changed the brushes, rotor, voltage regulator, and a few other minor things. $500 Lewbucks !!!! As E.T. would say Ooouch!

Thanks for all of the help guys!:D