help need fast fix

[tjjohnson91 10+ year member]

i have a 110ah battery alone sits at 12.55 and a walmart cheapo that sits at 12.7

My alt is a DC 250amp

okay........... well with one battery no amp car running it is 14.2 or so

when second battery is hooked up its reads 14.1

NOW added the amp ( DD z1) when just turning on it drops to 13.9

i turn the radio up it drops to 12.5 or 13...... but here is the messed part, it stays at that voltage in the back if not drops more...

but... the front battery still reads 14.2

ground?

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[skadude016 5,000+ posts]

possibly bac ground or also bad batt

 

[tjjohnson91 10+ year member]

but the battery reads just fine..... could it still be bad?

 

[audiolife 5,000+ posts]

reads fine off oc voltage or under a load?

 

[tjjohnson91 10+ year member]

reads good when nothing is on it............ with amp on just back battery no sound it dropped it to 9.5.....

also when i only have the car off and i turn the radio off it goes bomm through the subs butt...(pioneer deck) i have the rca's grounded, so i think thats that noise

 

[Louisiana_CRX 5,000+ posts]

I'd recheck all grounds including the decks