At a loss to why...

[lloyd&pamela]

The bus will not start now. The new 24 volt IOTA 25/27IRQ battery charger seems to be working fine. The green light is flashing bulk charging. The two 12v batteries are reading 15 v and the two 24v batteries are reading 13.7 each.

Vanner 1 is reading 12v = 15 / 24v = 28.7
Vanner 2 is reading 12v = 15 / 24v = 28.7

There is a bubbling sound coming from the two 24v batteries.

When I try to crank all I get is a click click sound.

Yesterday after installing the new 24v charger I ran the engine at high idle for an hour with no problem and the batteries and vanners checked out ok. The engine restarted fine and I thought everything was fine.

Tried to restart it a few minutes ago after talking with Denny and just click click click.

What am I doing wrong? Thanks again.

[mike kerley]

lloyd,

The four batteries in the engine compartment are starting/chassis batteries. All are 12 Volt batteries. Each battery, fully charged and not connected to anything should show approximately 13.4 volts. I'm guessing you looking at some larger batteries as well (8D's) that the house uses for electrical power. those are also 12 Volt batteries, just larger cells, giving more current capacity.

The four chassis batteries are connected in a "series/parallel" configuration so that you get the 24 volts at a combined amp rating. You must have two bad batteries. I'd disconnect everything and charge all four, wait an hour or two and check the voltage on each battery. my guess is that two of them will drop significantly. You most likely need to change all four.

The Iota chargers (I have two) on my bus ONLY charge the 4, 8D (big house batteries) and not the chassis, starting batteries which are only charged by the engine alternator or the small trickle charged I've added.

[lloyd&pamela]

No It is the four chassis batteries. wired for 12 and 24 the reading I gave are with them all wired together. Jim Craig from Country Coach told me which one were generating 12v and which were generating 24v that is the distinction I was making in the earlier post.

The house batteries are separate and working fine.

The IOTA charger I have is a 24 v charger connected to the chassis batteries in the engine compartment.

The reading seem to be strong enough to crank the bus.

I think I do have two bad batteries, most likely the one set for 24v since the new 24v charger has been running almost 24 house and is still bulk charging.

I was told Interstate would deliver anywhere. Is that my best replacement or should I replace with the same I have, AC Delco 31-900CT batteries? I would prefer to replace all with the same battery type.

What is the equilivant Interstate battery? Is it 27M-XHD?

Thanks

[Jon Wehrenberg]

I was afraid with the batteries being down to 10 volts or so that they may have experienced some damage. They need to be load tested. There is no other way to effectively determine their health.

If two are bad, the set of four needs to be replaced. We can discuss why all four need to be replaced, but to keep this short, accept that as the best course of action.

But.......something needs to be checked. If those batteries were fine before you lost the ground on your 50 amp plug, something else is at play here, because the DC electric and the AC electric systems are not related. What happens on one should not impact the other.

My bus sits for months with the chassis switches on and my batteries don't lose enough power to talk about. Yours seemed to go to hell overnight. Maybe it is just coincidental that by maintaining constant charging voltage you had them on life support. You went from charging voltage while driving, to charging voltage via the charger while connected to shore power. Or maybe something else is wrong.

If it were me I would not replace the batteries until I had verified there are no unknown chassis battery loads, the charger is functioning properly, it is wired properly, the equalizers are in fact OK, the bus alternator is OK, and the batteries, when tested did show that they are bad. If you tell me the batteries are five years old, I can fully understand what is happening., but not if they are a year or two old.

[lloyd&pamela]

The batteries are probably 5yrs old or older. They were at least three when we bought her and that is 16 months ago.

Remember the 24v charger shorted out and was probably creating a drain on the batteries until it was replaced and the trickle charger was just holding everything together.

How do I "verified there are no unknown chassis battery loads, the charger is functioning properly, it is wired properly, the equalizers are in fact OK, the bus alternator is OK, and the batteries, when tested did show that they are bad."

Who can do that, since I can not crank the bus now.

If and when I replace the batteries what batteries should I replace them with?

[Jon Wehrenberg]

The bus was originally supplied with Delco 1150 batteries. There are other direct equivalents.

You will hear the laughing, but the quickest way I have of determining if I have any phantom loads is to get the back of the bus inside where it is dark (or at night), and remove a 24V battery cable. If there are any loads at all you will see a small spark as the cable is removed.

Or you could do it the way technicians do it. Use the amp function on a tester to see if there is a current draw.

Now that you have said they are five years old, I would just load test the batteries you have, and assuming two will test bad, replace the set. At five years of age they are about finished.

[lloyd&pamela]

Yes the 24v side of the batteries sparked yesterday when I removed the cables to charge them individually.

Can I have the new batteries shipped here and install them myself or should I try to find someone to do it locally?

Is a load test something I can do? If so how?

[Jon Wehrenberg]

You need a load tester. Any battery store or service shop can test them.

The spark indicates there is a current draw and whatever it is, it does not belong. Find it and make it go away. I have no clue what it could be, or how you will find it other than looking for wires connected directly to your batteries. If by turning off your 12 and 24 volt master switches it makes the load go away that is all you need to do for now, but NOTHING should be drawing current on the chassis batteries with the key off.

You can replace the batteries yourself, but if the Interstate guy will deliver them, maybe he will install them. He may be able to test the batteries also.

Just to avoid problems, before you remove any cables mark them so they all go back where they cam from.

[lloyd&pamela]

Thanks John...

[MangoMike]

Just to avoid problems, before you remove any cables mark them so they all go back where they cam from.

There is a lot of cross connecting and jumper cables back there and it's easy to get them mixed up while you remove the old ones. As Jon says mark carefully, plus take a pix before disconnecting. I also zip tie and multiple cables together.

Good luck.

Mike

[lloyd&pamela]

zip tie

Great idea, thanks Mike

[lloyd&pamela]

Found a local diesel mechanic that knows what I am talking about and has 4 of the batteries in stock. Make enough calls and someone will pop out of the woodwork. Thanks everyone for furthering my education.

[Petervs]

Mine has a diagram of the wiring on the 4 chassis batteries, it is a label on the inside of the right side engine bay door, provided by Prevost when they build the coach.

[lloyd&pamela]

I have the diagram in the same place.

[phorner]

LLoyd,

When I did mine, I took several digital pictures before I touched anything, just to be on the safe side.

As a side note, our bus has a couple of yellow wires connected directly to the batteries, so in our case, we cannot get to a point where we have zero "phantom" loads on the chassis batteries.

Also, when I took mine apart, I had a couple of short cables that had corroded ends. You might encounter the same so be prepared to change them if necessary. You will be doing yourself a big favor if you correct any "bad" cables while you have everything apart. Most auto electric/battery shops have cables made up and can custom make them if need be.

Good luck....

[truk4u]

Lloyd,

Make sure the mechanic understands the series/parallel set up and doesn't mix up the cables, happens all the time even though they say they know what they're doing! Also, be sure to unhook the ground cables from your Equalizers before starting the work in case there is a boo boo..:(

[lloyd&pamela]

We got out the labler and labeled each zip tied set 1P positive 1 N negative, 2p 2n 3p 3n 4p 4n

Shot half a dozen photos and drew a diagram also.

he brought National Batteries that are equal to the Delco. I asked for him to bring Interstates tomorrow that are 900amp equivalents to the Delcos. I understand Interstate will warranty them at any dealer. If he can not find the exact one the Chevy dealer can have the Delcos overnight.

Thanks for all the handholding.

[Larry W]

I replaced the chassis batteries a couple of months ago with Interstates. They work fine. Took a photo of the batteries before I started and then printed a 8X11 copy. The photo of all the cables was great in putting it all back correctly.

[Alek&Lucia]

Lloyd,

Prevost is using Interstate Workhorse Group 31,
Here is a photo of our set-up with out the cover:

Alek

[Coloradobus]

The last time I replaced our chassis battieries I did the following.

disconnect and tape all cable ends and label.
Slide a 3/8 board under the loosened cables
Tape all calbe ends cllusters to the board and mark their position.
Raise board up with cables all taped as high as cable slack allows.
Slide the old batteries out and replace with new
Lower board
Untape the cables from the board, slide it out and the cales should be in the general vicinity of their terminal.
Attach all cables to their terminal and tightened.

Did this in January before we headed to TGO and it only took 15 miinutes to change them out.

Mind you each coach is different and I found this out with friends in Florida who I helped change their's out, The first cable for our coach to remove as to not have reverse polarity was different in theirs.. Both are Marathon "H"'s but theirs 48 coaches newer and closer to an 2001 model than ours which is also a 2000.

[lloyd&pamela]

We installed the new Interstate 31-MHD batteries this morning and everything is working and starting correctly. Well everything except the bedroom roof air. I think we shorted something with a surge. We never use it because it freezes Pamela but will have it looked at later. We need to eventually replace them all for ones that will cut off when they reach the proper temperature. Our are so old that they just keep running and the compressor comes on and off as needed. Very noisy. I hear the new ones are much quieter.

THANKS EVERYONE FOR ALL YOUR HELP AND EDUCATION.

[Alan__]

Lloyd, are you sure that it is not your thermostat that controls whether the fan is always on? On our thermostat I can program it either to have the fan on continuous or shut off when temperature is reached. I am of the camp that doesn't want the fan running if the compressor is off but some like it the other way to keep circulation going.

[lloyd&pamela]

Our system is eighteen years old and it is either on or off, it is not programable at all.

The problem is they do not make this thermostat anymore and you have to replace the entire system. The front AC only works on high but we normally just use the galley one.

Since it will require a complete replacement of all three to we have decided to wait until more of them died. So after OKC it might be time for a new AC system.