battery or alt problem???

[rebelfromva 10+ year member]

Was showing guy at work system today. I have my gain set for vol. 50. Noticed once past 45 today it kinda sounded like the sub was bottoming out. This is first time this has happened. I checked volts at amp fuse holder and second batt. All say 9.25 but when i check up front i get 12. Something roughly. Drove home. Checked volts at amp and got 9.15. What do yall think?

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[mylows10 5,000+ posts]

sounds like bad voltage reg. in the alt

 

[BrownVanMan 10+ year member]

disconnect rear batts and amp. and see what voltage you get off one of the batts

 

[All_Logix 10+ year member]

I bet you are getting extra resistance somewhere that is causing a voltage drop. If the voltage regulator on the alt was going bad you would have varying readings all over the vehicle not just at the amp. You can look into this because I have seen it before, one of the ends of the fuse holder or the terminal on another battery is loose.

 

[rebelfromva 10+ year member]

I bet you are getting extra resistance somewhere that is causing a voltage drop. If the voltage regulator on the alt was going bad you would have varying readings all over the vehicle not just at the amp. You can look into this because I have seen it before, one of the ends of the fuse holder or the terminal on another battery is loose.

Ideal said something similar to this. Imma have to fight my box around and out the trunk on Mon, check all connections and do some readings. I know you cant really tell what the problem is without doing a thorough search but from what you said it more than likely is not the alt? I wanna replace the stock alt with a ho just dont want to jump the gun til I fully know. Also any suggestions for a ho for my cobalt?

 

[All_Logix 10+ year member]

DC Power, Mechman seems pretty legit now, Ohio Gen if you have the money. Just make sure you got with a respected company and not some ebay small dealer. Dont get me wrong, some people have had good luck, but statistically the odds are against you there. Anyone can add extra winding to an alt and call it HO, but it takes some know how to make it dependable and work correctly on varying rpm