chassis batteries

[Jon Wehrenberg]

There is not only inconsistency between the different converters, there are differences in the coaches by the same converters.

My Elegant Lady has a chassis battery charger. Some Liberty coaches do not. So it is no wonder there are differences between converters. But as a coach changes hands the owners also modify the coaches so it is important to either get a very thourough checkout on the coach when you buy it (nobody does because they are so anxious to drive it) or spend the time required to look and learn every feature and device.

I'll repeat this again: If something is pulling down your chassis batteries you need to find out what that load is. There should be no loads on the chassis batteries with the key off, and ESPECIALLY with the large Prevost master switches turned off. If that is not the case, at the very least you have a fire hazard, and you likely are going to have battery problems plague you during your years of ownership.

[truk4u]

Darl,

Toy Box has a good point on the breakers. You need to be a little more specific on a couple things.

1. You tried to jump start using the 24V Prevost lug with a 24V source?
2. You said you charged the batteries with the stud, was your charger 24V
3. If your getting an equalizer light now, you may have fried it
4. When you load tested the batteries, did you unhook them completely
5. We assume the 24V and 12V cut-off switches are on
6. Is the rear start switch in the normal position
7. Do you have the digital dash

[Danss]

Just went thru same thing. I only have small 12 volt charger so I unhooked all wires and charged each battery 24 hours and everything works fine. I do have a 24 charger on order to have a permanant solution. Before charging, I would only get a clunk when turning key on. Best of luck, Dan

[Darl-Wilson]

Darl,

Toy Box has a good point on the breakers. You need to be a little more specific on a couple things.

1. You tried to jump start using the 24V Prevost lug with a 24V source?
2. You said you charged the batteries with the stud, was your charger 24V
3. If your getting an equalizer light now, you may have fried it
4. When you load tested the batteries, did you unhook them completely
5. We assume the 24V and 12V cut-off switches are on
6. Is the rear start switch in the normal position
7. Do you have the digital dash

Tom, Jon, Danss and Toy Box, Thanks for the good advice. I just finished going through everything you recommended but everything is essentially the same.

First this problem was caused (I think) by leaving the key in the accessory position for a long period of time. I have never had a problem with a parasitic drain in the 14 months I have owned this vehicle and nothing has been added that would cause a drain. In the past it has been idle for almost 2 months at a time with the 12V and 24V switches engaged.



Toy Box; The 1st thing I did was check the red breakers, making sure to press them firmly. None were tripped.

Tom;
1. I thought my charger was 24V when I used it on the Prevost lug. It is 12V.
2. I disconnected each battery individaually and checked each with a load. They indicated a about 12V before the load was applied and slightly less after. The instrument instructions states they can go down to 9.3V at 30 degrees. The temperature is a lttle less than 30. All batteries check the same with only a slight variance.
3. I topped off each battery separately, each disconnected from the other. 4. No indicator or voice regarding the "equalizer".
5. 12V and 24V switches were on in previous check and same today.
5. Rear start was and is in the 'Normal" position.
6. Dash is analog.

When I tried starting I could not hear a solenoid click or any other noise from the cab or when attempting a rear start.

The battery gauge inside the bus moves up slightly and the charge indicator shows 14V.

The fuel gauge does not work. Not all marker lights illuminate but the headlights come on bright. The turn indicators do not work at all.

The coach is plugged into shore power so the coach batteries are fully charged. The 17.5 KW power plant fires up and runs great. When this problem first occurred I ran the generator for a while hoping that it would charge the chassis batteries. ( I think I read somewhere on the Forum that some coaches are configured so the generator will charge the chassis batteries.)

In my original post I noted that the 2nd insurance service provider that tried to jump the batteries connected his vehicle battery jumpers directly to my bus starter which started my engine. After running the engine for well over an hour nothing changed. It would not restart.

I am completely befuddled by this problem. In the end I tend to believe that the batteries were never really dead but if that were the case why would the engine fail to start or at least make a clicking sound from the solenoid?

This is a '97 Country Coach XL45 but has a '96 chassis.

The engine/computer is a Detroit DDEC-III.

Logically this seems like a simple problem to remedy but my old brain is not working logically. If anyone here has an idea, no matter how absurd it may seem please let me know.

Thanks, Darl

[Jon Wehrenberg]

Darl,

When you turn the key on are you getting all normal dash indications, such as the gauges and the indicator lights, and if so does the two go out to indicate it is ready to start?

It sounds like a tripped breaker in the big box in the rear or a bad relay. I'm not at the bus and don't have my books, but my first guess is there is an open circuit somewhere because your voltages seem good.

[Joe Cannarozzi]

Two more things I would check.

First the ground. If a thorough inspection of that checks out:

Next check the smaller wire to the starter for a loose connection, also check the post it is attached to to make sure it cannot be twisted and is firmly affixed to the solenoid.

If that checks out then have someone put the ignition switch to the start position while checking that small wire at the starter with a circuit tester, it should light up in start mode.

If the wire is tight and it does light up, I'm baffled cause you said that it started with a jump at the starter. If you get lucky you will find no juice at that wire, or a bad connection.

If it shows no power and the connection is good the next place to go is the ignition switch and its circuit protection with the circuit tester.

[Jon Wehrenberg]

Darl,

Forgot to mention, when I had a problem with a tripped breaker (one of the big ones) I pushed hard and it seemed like it was set. I checked with my meter and it was still tripped open. I finally had to use a tool to push on it because I could not exert enough pressure with my thumb.

It may be worth verifying all breakers are closed.

Not hearing that click means that the engine run relay (solenoid) isn't closing.

I'm going down to the bus rather than guess any more.

[Jon Wehrenberg]

Darl,

I'm a little bit smarter now that I looked at the bus. Not much but a little.

Here's my recommendation. Make sure you have 12 and 24 volts in the coach. That is step one. There are a number of places to check such as the posts in the box in the rear and at several point in the front box. I suspect from your description of what you have and what you do not have working something is funky.

You need to verify those breakers are closed (the big ones on the side above the black master shut off switch.

Then check all the small breakers in the front and rear electric boxes. Several relate to the start and run circuits for 12 and 24 volt. Pushing the circuit breaker trip button and resetting is all I would do at this point.

Then using rear start see if it will start from there. When you hit the start button you should simultaneously hear R4 (the big relay or solenoid) and the starter on the bus. If not, test for power to R4, with the start button pushed, and check for a complete circuit between the two big posts to insure power is getting to the actual starter solenoid coil. If it is, follow Joe's post. If it is not check the relays for 12V and 24V run front and rear boxes. I think they are R53 and R54 in the rear.

It is just a question of finding where the electric from the batteries stops.

[Darl-Wilson]

Jon and Joe, Since it is colder than a witches 'you know what', I will wait until the morning and go do the things you two suggested. Actually I do not have a full dash. The voltage and battery gauge work but the fuel indicator does not. It seems to me like a fuse or breaker problem since it occurred while the bus was parked and I wasn't poking around inside any of the various compartments. Regardless, I will check it out in the morning and let you know. I really appreciate your help! Darl

[Jon Wehrenberg]

Darl,

I'm going by memory from something I think I picked up a long time ago so it may not be accurate. Some of the dash functions are controlled by some of the relays or breakers in the rear. As you mentioned you do not hear the click when the key is turned on but that indicates to me that a CB tripped or one of the relays is not functioning. Since the rear start also does not function you should look for a relay or breaker common to both front and rear start.

I'll poke around in the AM also and pull up some wiring diagrams if they are readable. It has to be something simple.