Originally Posted by Vicap
This morning the chassis battery was dead on my 2021 Tellaro 20kt. There wasn't enough juice in the house battery due to several days of rain/overcast skies not allowing solar panels to charge them. I plugged the RV to shore power & after a few minutes, was able to start the RV off the house batteries. A yellow check engine light is now on.
So my question is: would the house batteries drawdown drain the chassis battery?
Does a drained chassis battery automatically cause a check engine light to illuminate?
Ideally, the house batteries are isolated from the chassis battery to prevent just this occurrence. There should be a battery control center or at least a solenoid that keeps batteries isolated.
Is it possible something that draws from the chassis battery was in use or left on? Common items might be the dash radio or lights such as glove box or map.
In my career, when jump starting a dead battery, I would not allow the driver to get inside. I would hookup jumpers and we would both look in a window. Many, if not most times, there was a light that came on or a key left on. You see, lights always go out on their own once the battery goes down.
The check engine light is likely related to low power and / or the recharge. It would be a good idea to stop by a major auto parts store, like Autozone. They will scan the code that turned on the light and tell you what it is, at no charge.