Prevost battery question

Busted Knuckle · November 13, 2011, 11:51:06 AM

OK I just had a phone call from my buddy that runs Clarke Power Services Jackson, TN location (well until it closes down @ the end of the month)

He is working on a '94 Prevost w/60 series in it. (he thinks it's a Liberty)
They put 4 new AGM house batteries in it yesterday and hooked it all back up like it was. House system is set up a 12V system.

Well the guy drove it home and today it's dead as a door nail. He's out there on a service call and checking things out. One of the things he's found is that the battery equalizer on it has the ground hooked to ground, the 12V side hooked to 12V and the 24V side is also got 12V to it.
Now as I was trying to decipher exactly what he has I asked him if it was indeed a house system, or the start system.
He said it's in the back of the rear bay, and the start system is in it's own compartment behind that. (I'm sorta confused on that one, as I'm only used to the late '80's very early '90's Prevost batteries being in the back wall of the rear bay. But I have never worked on the batteries of a PROVOST conversion so I'm sorta out of my league here)
He's trying to get it charged up to start it, but it's a 24V not 12V like he thought! (He's used to trucks, and the 12V house system through him off.)

Any ideas?

BK

Hard Headed Ken · November 13, 2011, 12:38:22 PM

BK, my 1988 Prevost Angola conversion came with a 24 volt house battery system because it is more efficient to convert 24 DC volts to 110 AC volts than 12 to 110 and the 24 volt charging system is already there. 12 volts for house system needs is pulled out of the middle of the group. A separate equalizer is used for the house batteries so they will charge evenly.

Ken

luvrbus · November 13, 2011, 01:10:57 PM

Bk,the wiring is supposed to be

Red = 24 volts
Yellow= 12
Black = ground

maybe he missed a wire

Busted Knuckle · November 13, 2011, 01:29:28 PM

Ken & Clifford,
Thanks I'm trying to reach him now to see exactly what he has. Had to leave a voice mail waiting on a return call.

The way he described it the house bank was the only one on the equalizer in question. I didn't think to ask if it had 1 or 2.
He did say it only had the one huge 24 Volt alt on it.

BK

prevosman · November 13, 2011, 03:42:32 PM

BK, First, if it has 4 batteries it is unlikely a 12 volt coach. I say this because a Series 60 is one of the newer models and thus is liklely an Elegant lady which was a 24 volt coach.

The mention of a Vanner seems to confirm my opinion because you don't have to equalize all batteries if they are only in parallel. Verify I am correct by looking in the second drivers side bay and if there are a bunch of PLCs on the back wall it is a 24 volt house.

So whoever changed batteries needs to get them wired back the way they should be.

Adding to the confusion is when the discussion swings over to the chassis and not the house. The chassis on all the Prevosts I have seen has 4 group 31 batteries connected in series and parallel and the chassis uses a pair of 50 amp Vanner Equalizers, or on later models a single 100 amp Vanner equalizer (like the house on a 24 volt Elegant Lady.) The wiring diagram for the chassis batteries is oin the RH engine side door next to the batteries and it is VITAL they get connected together in that fashion.

If this is a chassis issue and not a house issue all the electrical diagrams specific to the serial number of the coach can be found here: http://prevostparts.volvo.com/technicalpublications/en/wiring.asp

Hope that helps

Busted Knuckle · November 13, 2011, 05:34:46 PM

Jon,
Thanks for the reply. Brent hasn't called back. I'll check with him in the AM.

I did ask him specifically if it was the house or chassis system he's working on. And he said HOUSE 4 12 Volt AGM's (@ $500 + each) in parallel.

I don't know anymore about it other than it's a '94 model and he did say the engine or chassis was 24V.

BK

prevosman · November 14, 2011, 04:34:03 AM

I may learn something here because the 12 volt Liberty Classic has 3 house batteries (8D) but the Elegant lady at 24 volts has 4. If he has a 12 volt four battery house it is either a coach built prior to Liberty going with a 24 volt house (the series 60 suggests to me that ain't so) or he has a special.

Would like to hear the results especially since the house batteries have absolutely nothing to do with starting, and Liberty does not offer or install a means by which the house batteries can be in parallel with the chassis batteries to start a dead bus.

I have fielded a considerable number of phone calls and emails from folks that changed chassis batteries and then couldn't get the bus to start. My advice (assuming he is talking about chassis batteries is to check the wiring. After he is done checking the wiring against the diagram, check it again. The final step is to check it again.

Busted Knuckle · November 14, 2011, 08:29:27 AM

I just talked to Brent and he had to contact Liberty about it and they sent him a wiring diagram this AM.

He said it was not even close to being wired like it was supposed to when it came into his shop last week and he & his guys just reinstalled it as it was.

He is going through and redoing or undoing what someone else has done.

BK

Oonrahnjay · November 14, 2011, 08:34:36 AM

Quote from: Busted Knuckle on November 14, 2011, 08:29:27 AM(snip) He is going through and redoing or undoing what someone else has done.
BK

Yeah, I'm sure that none of us have ever seen THAT movie ...

prevosman · November 14, 2011, 10:22:22 AM

Quote from: Busted Knuckle on November 14, 2011, 08:29:27 AM
I just talked to Brent and he had to contact Liberty about it and they sent him a wiring diagram this AM.

He said it was not even close to being wired like it was supposed to when it came into his shop last week and he & his guys just reinstalled it as it was.

He is going through and redoing or undoing what someone else has done.
BK

That is when I usually get the phone calls. After someone who was a "mechanic" or "knows buses" has replaced the batteries. Free advice to anyone contemplating battery service or replacement........Mark every battery post and cable end with corresponding numbers. Then get out the phone or camera before anything is taken apart and photo everything in detail. I have changed out 4 sets of batteries so far over 21 years and I still do that plus I make a diagram before I take it apart.

Of course we all know what free advice is worth.

Busted Knuckle · November 14, 2011, 12:23:34 PM

Quote from: prevosman
That is when I usually get the phone calls. After someone who was a "mechanic" or "knows buses" has replaced the batteries. Free advice to anyone contemplating battery service or replacement........Mark every battery post and cable end with corresponding numbers. Then get out the phone or camera before anything is taken apart and photo everything in detail. I have changed out 4 sets of batteries so far over 21 years and I still do that plus I make a diagram before I take it apart.

Of course we all know what free advice is worth.

Yes I know the feeling. I only get the call AFTER something that was put back together EXACTLY like it was took apart, and then doesn't work right.

I also have changed out batteries on different model coaches many times over the yrs and still number & diagram everything.

BK