Getting bad voltage drop.

[j_1990]

Hello everyone. I have 2 sundown audio sd-2 10 inch subs with a kicker zxs 1500.1 amp. 1500 watts rms total. I have a high output 250 amp alternator from mike singer. I have the big 3 done in 0 gauge wire. Also i have an oreillys battery 750cca under the hood. Its not an agm batt. Now my problem is when i turn my system up and the bass hits i see my voltage dropping real low on my dash gauge. Like on some bass notes it drops to 10v. I have tried to add a second stinger battery but that did me no good so i returned it. I emailed mike and asked for some advice and he recommends me adding an alternator ground to the - battery terminal. Waiting for the wire to come in the mail. Just wondering if anyone here might know if the extra ground wire will fix this or if there is something else that is needed. Oh yeah and the vehicle is an 89 chevy truck. Ground and power wire from amp are good. Any advice will be greatly appreciated. Thanks!

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[Imtjnotu 5,000+ posts]

do u have a quilty meter on hand...try having a meter on ur batteries and seeing what ur voltage drop is during a song instead of a cheap voltage gauge

 

[supra1987]

A better ground on the alternator won't fix voltage drop but is definitely good to do and probaly help.an agm battery up front would be a good investment

 

[j_1990]

I dont have a meter on hand. How big of a differnce is my dash gauge from a meter?

 

[j_1990]

I tried the duralast platinum which is an agm battery but that barely helped any. I might need to try a better quality battery

 

[j_1990]

Tried the alternator ground. That didnt help any. Does anyone have any other advice?

 

[Dmac1991]

turn the gains down?

 

[dragon.breath 10+ year member]

Before you do anything else, go buy a digital multi meter. You can get a basic one for about $20 at Walmart or lowes. The factory voltage meter in any 20+ year old vehicle is going to be suspect.

 

[CrossoverOre 10+ year member]

have the main battery tested.

 

[j_1990]

Yeah ill have to get the battery tested and the alt while im at it. Was thinking about getting a die hard platinum but all i can find on sears website is the marine batteries. Seen one on ebay for sale for $100 that has 930cca but i dont really want a used battery. Any suggestions on a good agm battery for under the hood for a good price?

 

[soundstreamer 10+ year member]

The amp is grounded to the body right? My '89 chevy had nasty dimming lights with a 1000 watt amp grounded to the body, then later with 7000 watt amps and direct to battery connections didn't have any dimming. Run body to chassis ground cable, ground directly to frame, or directly to battery. If already doing that then I typed all this for no reason and nevermind...

 

[mylows10 5,000+ posts]

The gmc and Chevy trucks. Have bad electrical a to start with anyway. Get a good agm under the hood. Maybe an extra one in back to run a ground from front battery to the back. Then to the amp also like said. First check voltage with a dmm and set the gain properly I suspect the gains at 3/4 if the way up

 

[slvrado28z 10+ year member]

need to ground strait to frame...I had a truck like this and grounded to front seat bolt and had the same problem.

 

[j_1990]

Yeah thats what its currently grounded to is one of the bolts that hold the seat down. Ill try to ground it directly to the frame. The gain is only halfway. Also my protection light on my amp blinks every time a hard bass note hits. It blinks with the bass notes. Ill get the battery tested as soon as i get a chance. Thanks guys for all the advice. Ill report back if i still cant figure it out.

 

[j_1990]

Alright thanks guys. I grounded my amp directly to my frame and my voltage has improved. It only drops to about 12v now. Next ill get a good agm batt. Thanks for all your help.