Dual battery problem...

[mtntruckin]

My '01 2500 came with the factory camper option, dual battery setup. From what I've found, it should automatically change over to aux power when the engine is off. When I run my stereo with the truck off, I get maybe 20 minutes of power and the truck is completely dead. The auxiliary battery is a little corroded. Any ideas? Should I swap both batteries for new ones?

 

[happy 2011]

have the battery tested at a shop.

 

[kniki10]

There may be loose connection in the battery, so u can think of getting it tested at a dealer.