Dead Truck?

[thisflatearth]

Went to start my truck this morning and it was dead, no head lights/interior lights, nothing.

 

Didnt have time to check the connections or anything aside from grabbing with my hands and trying to move them. Hooked it to my minivan and it came to life started no issue. Drove to work no issues except for resetting the clock.

 

Its a 2007 3500HD dual batteries, 6.0. I was under the impression that the dual battery setup kept them isolated and saved one for starting?

 

Am I wrong?

 

They are the stock batteries from 2007. Never ahd an issue. Nothing was left on over night or plugged into the power sockets. It sat for 2 days unused and then last night my dad moved it about 10 feet in the driveway.

 

Ideas?

 

Tomorrow morning I will check the connections and see what kind of voltage I have in both batteries. Alternator looks like its doing its job according to the dash gauge.

 

Thanks

Dave

[8.1HD/ALLISON]

I don't believe the stock setup is isolated. I would disconnect them and test both batteries.

[cfeiring]

Both batteries are not isolated from each other.

Disconnect one battery at a time and test, to get the results for that battery.

Could be that the batteries have just reached the end of their service life.

I had a battery do that once just like yours; one fine and the next morning dead no warning by slow starts or anything.

[thisflatearth]

Yeah, just went out and checked them without disconnecting them. I got 12.8 on one and 13.15 on the other, so it seems like they are isolated when the truck is off, will confirm with the dealer on Monday.

 

The connections feel tight to the hand and show no corrosion.

 

Now everything works like it should. Before the keyless entry and interior lights nothing.

 

Now when you hit the key fob the lights come on it unlocks, relocks with button and sounds horn.

 

Will keep eye on it and will get the batteries load tested ASAP.

 

thanks

[builderpaul]

You probulby have the isolated since it is a 6.o only the dmax come non isolated. The isolated and main are only connected when the truck is running. No need for the minivan you should be able to jump from the aux to the main for starting. This system is made so you can run the aux bat down and still start, not the other way around. Don't know why it should die after only 2 days of inactivity. You need to check the drawdown when it is not running. Pull diffent fuses to see what is taking the power.