Batteys

Mandalay Parr wrote:
Might replace all batteries.
Without known good ones you are just 'shooting in the dark'.

Might NOT too.
Spending money on a wild guess is not good advice.

Some simple testing should uncover the cause and what to do to fix it.

No single cause should discharge BOTH sets of batteries.

I could go along with this IF both batteries are the original OEM ones; going on 6 years old now.

Might replace all batteries.
Without known good ones you are just 'shooting in the dark'.

farmingdad wrote:
Just bought a 2011 mountain air and the coach battery's and chassis battery's go dn owner night why, the light switchs stay lite with a dim blue light all times I don't no if there is away to cut them off

Assume you said go down overnight;
1)once the batterys get low unless you give them a super charge and not simply a surface charge they wont hold there charge
2) the fact the two start batterys and the 4 house batterys both lose their charge is extremely unusual
3) there must be a parasite load somewhere but how it effects house and chassis is a but strange
4) I would start by making sure both sets of batterys are charged up properly then disconnect both sets and let set for 24 hours
then meter them and if their low replace
if there still charged (12.5-12.8 volts) and the house at each over 6.2 volts or so then you have major power draw somewhere
but as said weird its effecting both battery packs though
at 7 years of age it may be you simply need new batterys both house and chassis
an expensive DPMH like a mountain air I would assume it has both a house and a chassis battery disconnect system though

Until you find the problem this will cure it:

Battery disconnect switch.

How old are the batteries?

Is there water in the batteries?

Are the storage bin lights turned on?

Do you have an inverter?

farmingdad wrote:
Just bought a 2011 mountain air and the coach battery's and chassis battery's go dn owner night why, the light switchs stay lite with a dim blue light all times I don't no if there is away to cut them off

Is this a full electrical coach?

Our's is not, but the batteries will drain when the heat is on, the blower uses a bunch of battery.