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Robert, RV Mechanic
Category: RV
Satisfied Customers: 13357
Experience:  18 yrs. RV experience including Cummins North West, Country Coach, Monaco Coach - vendor certified.
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Monaco: chassis battery are..engage..light comes

Resolved Question:

I have a 07 monaco dynsaty isl 400.... When i am contected to shore power, my house batteries are charging but my chassis battery are not... when i am plugged in, i have no lights on the big boy panel, i can hit the ser button to engage and light comes on.. Checking voltage on the big boy the left side has 13v the right has 11.9... on my batteries. the house has 13v the chassis is 11.9.. does this mean my big boy is bad.. tx
Submitted: 5 years ago.
Category: RV
Expert:  Robert replied 5 years ago.

Hi There!!


Thanks for Choosing Just Answer..


Can you tell me what the ser button is you are referring to?


Thanks, Robert

Customer: replied 5 years ago.
on the panel where the big boy is.. on the right side of the circuit board there are lights, and 2 small buttons when i push one of them i hear the big boy click and a light lights up.. when i push the othe one a selonid on the same board clicks, and a light lights up
Expert:  Robert replied 5 years ago.



I am pretty sure the Dynasty does not charge the house battery when plugged into shore power. Some Monaco's do but I am fairly certain that the Dynasty does not. There will be a few solenoids, normally the big boy is the house solenoid that feeds power into the interior. Also there is a bi-directional solenoid, and what this will do is allow the house battery to charge when certain demands are met from the alternator. When you are running your engine and the voltage is above 13.3 volts it will allow the house battery to charge.

I have a feeling that is what you might be looking at and a test would be to start the engine and get some voltage readings off of that solenoid. IF the voltage goes up on the chassis post and then goes up on the house battery post (above 13.3 volts) then it is for charging the house battery while driving to maintain the battery.

I would call Monaco Tech Support to find out for sure. Do not want you to replace parts that are not needed. IF that is the case a Trik L charge or echo charger can be installed that will allow that chassis battery to charge when plugged in.



Customer: replied 5 years ago.
The problem that arose and me started checking is that i have had this coach since new... i was plugged in this last month, and couldn't start the engine, the engine batt were dead, after charging up and load testing the battery, they are fine.. there is a 4ga wire directly to the + side of the battery that is not controlled by the cutoff switch, that 4 ga is always hot and goes into that run box, there is a 30 amp engine fuse on that board. that is drawing power on my engine bat... after talking to monaco they told me, that fuse is the ecm on the engine, and that is always has a draw, he said the problem is, that my chassis bat aren't charging, thus casusing that draw to kill the batteries.. so i started checking power, and thought by what i was reading that the voltage on the big boy should be the same on each post, now i'm confused...
Expert:  Robert replied 5 years ago.



Click HERE and is this what you are looking at? I would call them back and find out if your unit charges the chassis battery plugged in. IF so then it could be that solenoid it would be the only item to allow charge, if not you can add a echo charge to keep the batteries up.

I just don't want you to replace that big boy and have the same issue. I understand what you are saying, you should have incoming voltage, one post going to chassis and one to house. I would see if you can test that by running the engine and seeing if that is opening up allowing power to the house side above 13.3 volts.

Someone needs to pull a print and look for you. I looked at a 2005 dynasty print and there was no indication that it is getting a charge from shore power.



Customer: replied 5 years ago.
While my coach is running.. the chassis batteriers are charging fine... it is the shore power that i am trying to understand,.. Even when the shore power is contected.. and my battery disconect if off, engine and house... i still have a draw from the run panel, where the 6 pin conector is at.. which is fused by a 30 amp and 5 amp.. when pulling the 30 amp, i don't have the draw.. Monaco the that 6 pin is to the ecm, and i will always have a draw on that.. i will call monaco rigth now..
Expert:  Robert replied 5 years ago.



They are probably correct, but I would find out if this model charges, I did not think the Dynasty charged the chassis battery when plugged in and I have seen a few other manufacturers like this as well. And the only thing that can be done is add an echo charger that will charge. I will also see if I can find some more info out..



Customer: replied 5 years ago.
i sent you the my last message before accepting, not sure if you recivied it or not, But monaco said that my 07 does charge both, and the big boy.. which on one side has 13 the other 11.9, will not enerigize unless 14 volts are going into it, he said i should first look at my settting on the controll pannel and make sure it is set at the correct charging capaicty, and if it is, he said i may have a bad inverter/converter.. What is your assesment on that answer.. Thank you for your time, i will accept after hearing back from you... Is there a way to hire YOU again, or it is just the roll of the dice, Just like talking to a tech in person, its always better and quicker when the already know what there dealing wiith.. Again.. thanks jeff
Expert:  Robert replied 5 years ago.



No I did not receive credit, and you can accept any of these post if you feel like I helped..



Well that is not much room for charging the chassis battery but I guess it is designed to charge when the voltage is above 14 volts which is really never.... The way the inverter works is it charges in stages. So if the batteries were low the inverter would be in a bulk charge and charging around 14.2 volts, not much higher, after the bulk it will go down to around 12.8 and maintain in a float charge. So you can see that chassis battery is not getting charged that much, normally the inverter will charge like that in stages. SO IF you get me the model of that inverter I can find you something, and we can keep going, you been real patient and I enjoy helping out.

Let me know the model of that inverter. I have a feeling you will need an echo charger but lets see if that inverter charges over 14 volts all the time....


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