chassis batteries

[Jon Wehrenberg]

Darl,

I'm on my second cup of coffee and with wiring diagrams in hand I think the issue is one of not getting power to the start circuit.

Verify there is power at the starter. You should have 24 volts on the big cables, the positive and ground. The power to these terminals goes directly from the chassis 24V battery post, through the cut out switch to the starter solenoid post. I have two diagrams and do not know which is applicable to your coach. The second one shows a relay in that circuit, but I do not think that applies here. (That's a guess)

If you have power, then the simplest start circuit is the rear start. It has the fewest possible failure points. You should have 24V power at the rear 24V junction block. If not look at the 90 amp breaker CB5 which should be near your cut out switch.

If you have power, select rear start. Power then runs through CB16 to the rear start button, from there to the rear start switch, to the large relay (solenoid) R4 coil. When you push the start button in the rear you should get 24V at that solenoid coil, it should close the contacts allowing 24V to run to the starter solenoid coil.

Since you lack all dash gauge indications I'm thinking your problem lies with the 90 amp circuit breaker or a relay related to that if you coach has one.

Keep posting your progress. I'll keep checking back. bear in mind the wiring diagrams do not list coach serial numbers and I have narrowed it to the two which may be applicable. One has a relay but I suspect strongly yours (and mine) does not have that relay.

[truk4u]

Darl,

Thanks for the response, John's got you on the right track and I'm glad you don't have the digital dash. Some of the questions I asked sounded stupid, but it's easy to overlook stuff. Sure sounds like a breaker problem. You said the dash gauge showed 14V, what did the 24V gauge show?

Keep us posted.

[Alek&Lucia]

Hello Darl,

Your reading on your batteries should show: 12.7-12.8V not "...12V or just a hair less..." Your batteries needs charging.

[Jon Wehrenberg]

Darl,

Alek's post is correct. When I talk abouit 12V and 24V those are nominal values. At the 24V terminals on the starter and at the 24V post in the rear junction box you should see no less than 24.4 volts and the best voltage would be around 25.4

[Darl-Wilson]

Jon, Joe, Alek, et al, Thanks for all the help! I have followed your advice and here is where the situation stands; first I did the obvious (some of which I had done prior to my plea for help) checked the circuit breakers, like R5 and all the large 12V and 24V breakers near the rear cut-off switches. This time I pressed them extra hard and pressed the reset button on all the small breakers inside the rear engine compartment and in the compartment below the drivers seat. I tried to start from the rear. No luck. Same with the cab ignition. I then used my battery tester and came up with almost 13V on all batteries. Testing the the post with the red plastic cover on the starter, grounded to the frame, yielded a value of 13.3V. I didn't have anyone to press the starter button so I didn't get that reading. A reading from the jumper lugs was 12.9V. I decided to use a different electrical tester. I now have a 11.9V on the batteries with that tester and 12.3V, after applying a load for 15 seconds, using the other tester. At this moment I have my chargers on individual batteries that have been disconnected from the others. Charging at 10 amps for 2 hours.

I hit my head a 3rd time on the battery door light switch causing it to start bleeding again (some folks never learn), the outside temperature is now above freezing but the wind is blowing about 30mph with gusts to 50. The good news is the sun is shining! I will go out to check the charge in a couple of hours and post the results. Oh, the Battery gauge inside the bus moves a bit and the Voltage gauge reads 13.5 volts.

Finally, if the batteries test at 12V or slightly less wouldn't there at least be a solenoid click or would there just be silence?

Again, thanks to all. I will give you an update as soon as I have one.

[truk4u]

Testing the the post with the red plastic cover on the starter, grounded to the frame, yielded a value of 13.3V.

The red hot post coming from the batteres at the starter should be 24V or above. Fully charged mine reads 25.8. Maybe I misunderstood the above post.

[Jon Wehrenberg]

Darl,

I agree with Truk. The wiriing diagrams I have confirm you should have 24V at the big starter battery connections. The only 12 volt you should have is for DDEC.

Try not to bang your head any more, or at least wear a thick soft hat.

I don't know if you would hear a click BTW. at some low voltage DDEC is disabled and I don't know if other relays will fail to engage at low voltage.

[garyde]

Hi Darl. Depending on the age of your batteries and the number of times they have been drained down, they will not come back up. The best thing to do is to take them in and have them load tested. If they are all the same age and several are bad, replace all of them or the new batteries will get drained by the older batteries.
I left my ignition on by accident and drained my batteries down. Because I failed to check water levels & proceeded to charge the batteries, I fried them all along with my regulator. I am not saying this is your problem but a series of events can exacerbate a simple problem.

[Darl-Wilson]

Gary, the Interstate batteries are only 14 months old and still under warranty but I am beginning to think that is the problem. When I put my small, automatic charger on one isolated battery it charged up to over 13V. I am now charging a 2nd battery overnight and will check in the morning if the 1st held the charge. If they appear to be OK I will do what Tom and Jon suggest and check the output at the starter for the 25.8V that Tom gets at the starter. If that fails the next step will be new batteries.
I sincerely appreciate all the time and effort everyone is taking to help me with this problem. Needless to say joining the POG and meeting such great people has been a very rewarding experience.

I will post an update when I have completed the charging, etc.
Thanks!

[Jon Wehrenberg]

Batteries are underappreciated until we really need them. Isolating, charging and testing each one individually is the only way to verify they are all OK, and even at 14 months old if a single one is bad it may be better to replace them all. I hope that is not the case.