Alternator(s?) on 03 Liberty

[hobobimmer]

Are there 2 alternators on an 03 Liberty, one for house and one for engine batteries? We seem to not be charging as we roll down the road. Gauges and Liberty book indicate we must have some issue with our " alternator". Since gauge for engine appears normal, I assume there must be 2 alternators. Just fired generator up to charge so they don't drop too low. Any ideas what we look for when we get home tomorrow? Thanks everyone. Deb

[jack14r]

I had a 2005 and it only had one alternator,a 270 amp 24 volt,I would check the regulator as Prevost has updated it around 2008,I had one fail.The generator with the guest charger will keep the coach batteries up as long as you are not driving at night but the OTR will not work.

[hobobimmer]

Thanks for the reply.How does generator know if it is day or night? We have the Lady Classic with 12 volt system. OTr is working, or at least appears to be. We will look into our big book of details soon. I appreciate your info and ideas. Maybe ours is slightly different being a classic and not elegant lady. Readings on house monitor in dash with 2 house battery chargers on and generator running is +50amps and 14volts. Other dash gauge has been barely above 0 amps and 27 volts. That reading has been normal all day. Deb

[Jon Wehrenberg]

The Classis has a 12 volt house thus has the large alternator for the 24 volt Prevost chassis and a 145 amp alternator near the radiator for the house.

There are only two ways to charge the house batteries. Start the generator (or shore power) and the inverters become chargers or run the alternator off the engine. If the engine driven alternator is not working (run the engine and note the house voltage should go over 13 volts) it likely needs repair or replacement. Take it off and any local alternator shop can check it. It could be the internal regulator or the alternator itself.

[ajducote]

Deb,

If you have a 12 volt coach you must have 2 alternators. 1 each 12 volt very large one for the house batteries and a smaller 24 volt one for the engine /chassis batteries. Have you looked to see if you threw a belt on the engine?

[jack14r]

At night our current needs are greater because of headlights-that is what I should have said.

[gmcbuffalo]

Shouldn't you be able to check the voltage on the alternator with a multimeter? If you have voltage start following the wires.
GregM

[hobobimmer]

Thanks everyone! We will investigate when we get home. Deb

[phorner]

Our bus also is configured with a 12 volt system and the 12 volt alternator is located on the left (driver) side of the engine and is driven by a belt from the fan drive gear box.

Unfortunately, we have replaced ours twice already. Relatively easy fix, but not necessarily a cheap fix.........

[Jon Wehrenberg]

At that number of miles there should not have been a failure. At that number of miles two failures is ridiculous.

I think these folks make the alternator in question. http://www.prestolite.com/pgs_products/alt_search.php

[hobobimmer]

Back to square one for Debbie and her house alternator. After talking to alternator shop today, and learning how to use my trusty multimeter, Eric and I finally found time to investigate the alternator issue. This evening, with the bus engine running, the gauge on the dash read normal and voltage at alternator was normal (as checked with our multimeter). So now we know our problem must be intermittent, because it all sure seemed to be working properly this evening. I know for sure it has not been working 2 times, since the batteries were not charging when we were driving, and the gauge on the dash indicated that there was a problem. The batteries charge normally on shore power and generator, and they seem to hold a charge well, so I don't think it is a battery issue. Connection of big wires to alternator are both tight. Belt is good. So, question is this: does an intermittent problem indicate that the alternator is about to puke? Do we now remove it and have it bench tested or is it likely something unrelated? Did we just have a spontaneous fix????

Second question,is very specific to a 2003 Liberty Lady Classic. If we need to remove the alternator, I see the two mounting bolts, so getting it out doesn't look too hard. I would like to disconnect the battery supply to the alternator so we don't fry ourselves or the bus. I see the switch in the 2nd bay drivers side that says 12 volt House Battery disconnect. I assume this is what accomplishes this task. I confirmed this with Troy at Liberty told me all I needed to do was disconnect the battery here,simple as that, but when I opened that bay I saw a yellow sign below that cut off that says "Do not turn off house battery disconnect unless battery watchdog is disconnected. Failure to comply will result in generator control circuit failure. Heart Remote Panels must also be reprogrammed. See yellow instruction tag at 110 distribution panel" YIKES. Does this mean that if I don't disconnect the watchdog that all that bad stuff will happen, or does it mean that if I cut off watch dog, then disconnect the battery that I will still have to reprogram the heart remote panels? So, how do you disconnect the watchdog???? It is frustrating to know just enough to not know enough. But at least I learned how to use my multimeter today:) Deb

[Jon Wehrenberg]

Deb,

You can have an intermittent alternator. You can have a problem in the regulator or something internal to the alternator so my free advice is if you know the alternator has not been charging on at least two occasions, pull it and either get a shop to rebuild it, letting them know of your issue, or just buy a new one. When you run the generator or have shore power the inverters become battery chargers so if you do want to run the alternator to total failure it is not the end of the world. I struggled for a couple of years with an intermittent alternator on the plane. It always checked good and it drove me and mechanics crazy looking for the problem in the alternator or the voltage control units. I could reset it the voltage control unit circuit and the problem might not reappear for hundreds of hours. You could be dealing with an equally frustrating issue.

As to removing the alternator, if that is how you choose to go......If you choose to not reprogram the inverters or disconnect the Watchdog leave the bus connected to shore power in the barn. When you disconnect the wires at the alternator just remember they are "hot". That means if the big wire terminal hits a ground (anything metal) you are going to get a big spark, but you can handle that terminal all day long and nothing will happen to you because it is only 12 volts. Just carefully loosen the nut, and use care to not allow the wrench to come in contact with anything other than the nut, unthread it by hand with the terminal being held in place. When the nut and washers are off, remove the terminal and tape it to prevent it from accidently hitting any metal and grounding out until you are ready to reinstall it. Ditto on the other terminals.

Your inverters will keep the batteries charged up and the Watchdog and inverters will not even know you removed the alternator.

[phorner]

Deb,

For what it's worth, when I changed out our 12 volt alternator, I simply disconnected the leads and taped them to keep any accidental sparks from flying. There will be 12 volts coming "back" to the alternator from the battery bank.

Also, unless you have the bus set up with the generator set to auto-start, I don't see an issue with the battery watch-dog.

Once I had the leads removed and taped, I simply removed the alternator and took it to a local shop for repair. My problem was also intermittent and was likely a problem with the voltage regulator which in my case was part of the alternator.

Good luck with your project. It's much easier than you think.

Bring that bus to Port Saint Lucie and I'll be happy to give you a hand!:D

[hobobimmer]

Thanks, Jon. That is exactly what I needed to hear. Deb

[travelite]

Folks,

What does the Watchdog do?

[phorner]

The Battery Watchdog is Liberty Coach's generator auto-start system.

[garyde]

Hi Deb. I had a similar problem with my charging system. The guages were going haywire. I replaced the electronic voltage regulator which is attached to the wall above the batterries and all was well.
A Watchdog is Liberty's electronic box which will auto start the generator when the house batteries go low.

[Jon Wehrenberg]

Deb and Eric have a Classic which uses dual alternators and I think the house alternator has an internal regulator.

[phorner]

Deb and Eric have a Classic which uses dual alternators and I think the house alternator has an internal regulator.

Yep, I think so too, Jon.

Mine is set up that way..... and that's where the problem was in my case. So I had the alternator re-built (including a new regulator) and all is well.

[Jon Wehrenberg]

David,

Forgot to respond earlier.

The "Watchdog" is a Liberty proprietary generator auto-start and monitoring system. It will start the generator when house battery voltage gets down to a specific level, if set, it will start the generator upon interruption of shore power, and it monitors to make sure all operating conditions such as temps and oil pressure are within limits.