Coach batteries dead

[ky bob]

I started my Rv today and engine starts up ok, but house batteries have no juice. While the engine is running, the meter in the dash shows 13 plus volts charging and looking at the Magnum monitor shows “off” and DC 4.9 Volts 0 A

I checked one of the batteries with a battery specific gravity hygrometer and it shows it needs recharge.

It has 4 INTERSTATE batteries GC2-ECL-UTL .
I have the BIRD controller and the TROMBETTA INSTALLED

I have the engine running now and am at a loss of what to do next.
If the engine will not charge up the house batteries, do I just replace them ?

I jumpered across the trombetta relay by touching a short battery cable across the two large battery terminals and got a small spark and the engine sound changed a bit. I let go of the jumper and went in to look at the Magnum panel ant it was still saying off , but the DC voltage said 7.8 volts . After a minute it dropped down to 6.9 volts, and is now dropping a bit lower.
Did the spark indicate the relay is not engaged?


When the engine is running, should the trombetta relay be engaged ?

and with the engine running, should the magnum monitor be powered up ?

And with the engine running should the batteries be charging by the engines alternator ?

Advice is deeply appreciated.

Thanks,
Bob

[Persistent]

New batteries may or may not be necessary. First find out why the house batteries are not being charged. New batteries will be in the same discharged condition quickly if you don't fix the charging system.

The Thor RV has several points of possible failure to charge. The problem may be control settings, isolation relays, fuses/circuit breakers, disconnect switches, etc.

[ky bob]

OK , point taken about replacing the batteries.
But please answer these questions.........

1) should the Trombetta relay be engaged when the engine is running ?

2). Once the engine is running, should the power from the alternator be powering up the Magnum controller ?

3) what are the correct settings for the Magnum controller for my coach with the interstate GC2-ECL-UTL batteries my coach has ?
I am not sure of any of the settings as I just recently purchased this 33.3 Palazzo (2015 model).

Thanks

[twinboat]

Your trombetta relay is not closing. Try holding the boost switch to get a charge from the running main engine to the house batteries. If that don't work, jump across the large posts of the trombetta temporarily and see if that works.

If that don't work, follow the large cables. Each one goest to the house or start battery. May be breakers or fuses in that path.

[ky bob]

Originally Posted by twinboat

Your trombetta relay is not closing. Try holding the boost switch to get a charge from the running main engine to the house batteries. If that don't work, jump across the large posts of the trombetta temporarily and see if that works.

If that don't work, follow the large cables. Each one goest to the house or start battery. May be breakers or fuses in that path.

Holding the boost switch doesn’t seem to help, by I did not look at the Magnum controller when I pressed it . The trombetta relay is not engaged , because when I jumper across it , I get sparks,. If it was engaged, i would not get any sparks when jumpering across it.

I am still looking for the answers to the 3 questions I wrote in my previous post.

Thanks

[twinboat]

The alternator will first bring the chassis batteries up to 13.5 volts and then it will start to charge the house batteries.

It does not power up the magnum. The house batteries do that. They need over 8 volts in them though. That where the alternator thru the isolation relay can help, if working.

[ky bob]

I ran the engine for about 10 minutes and then checked the trombetta relay. There is no 12 volt dc at the terminals on the solenoid, so the relay will not energize and let the alternator charge the coach batteries along with the chassis batteries.

I followed the 2 wires connected to the coil on the relay.
One is the (white wire ) which is the ground that connects to the BIRD box on the GROUND terminal.

The other is the (purple wire with the black stripe) which connects th the BIRD box on the RELAY terminal.

Measuring across these two terminals , I get. ZERO VOLTS.

I checked voltage input from ignition on the IGNITION terminal on the BIRD box and I also get ZERO VOLTS.

I think I need to find out where the ignition wire gets its power.
Is there a fuse on this wire somewhere ?
If so , where is it ?

All help is appreciated

Bob

[twinboat]

Yes, you need power on the ignition wire. Can help where the fuse is, but it will be near the 12 volt source, not where it connects to the BIRD control.

Your ignition switch turns on a bunch of stuff and there should be a relay it controls and a bank of fuses to the accesseries.

[ky bob]

Originally Posted by twinboat

Yes, you need power on the ignition wire. Can help where the fuse is, but it will be near the 12 volt source, not where it connects to the BIRD control.

Your ignition switch turns on a bunch of stuff and there should be a relay it controls and a bank of fuses to the accesseries.

In the bay with the BIRD &. Trombetta relay, there is a black box with a cover on it. Inside are a few black square relays and fuses. I looked at the cover with the legend of what fuses are for , but I am not sure if any of these are for the 12 volt ignition supply.

If anyone has an idea if any of these fuses feed the 12 volts to the BIRD control box, please let me know.

[HJLowell]

Personally
I would charge your house batteries overnight and see if you can get them up to 12.6 to 13.5 or so.
I don't think you can do much trouble solving until you have well charged batteries .
You may also find out that they are cooked and need to be replaced.

Do you have 120 to plug a good charger in to ?

[ky bob]

Originally Posted by HJLowell

Personally
I would charge your house batteries overnight and see if you can get them up to 12.6 to 13.5 or so.
I don't think you can do much trouble solving until you have well charged batteries .
You may also find out that they are cooked and need to be replaced.

Do you have 120 to plug a good charger in to ?

I can charge the batteries, but.... I first want to know how to get 12 vdc to the BIRD control box.


If anyone know where this supply wire would be fused , I would appreciate it .

[HJLowell]

Originally Posted by ky bob

I can charge the batteries, but.... I first want to know how to get 12 vdc to the BIRD control box.


If anyone know where this supply wire would be fused , I would appreciate it .

Read #8. From twinboat
You have to charge your house batteries to 8 to 10 volts to jump start your inverter system.

From a remote source at this point I think.


I have to have mine at 10 on my boat to kick start my trace inverter.

[ky bob]

Originally Posted by HJLowell

Read #8. From twinboat
You have to charge your house batteries to 8 to 10 volts to jump start your inverter system.

From a remote source at this point I think.


I have to have mine at 10 on my boat to kick start my trace inverter.

I agree, and I will charge the batteries thru my power cord.



But if the batteries are dead or not, shouldn't I still have the ignition wire 12 volt supply to the BIRD controller when i have the engine running ??

[twinboat]

Originally Posted by ky bob

I agree, and I will charge the batteries thru my power cord.



But if the batteries are dead or not, shouldn't I still have the ignition wire 12 volt supply to the BIRD controller when i have the engine running ??

Yes.