280amp alternator with dimming head lights

[dgaf 10+ year member]

I have two SA15s running off a 2500 mojo.

A new optima yellow 34/78 battery and a dc power 280amp alt under the hood.

Big 3 done with 1/0 wire, solid ground.

Headlights dim. Not sure what the voltage drop is, I should probably check that out, would do it now, but it's raining.

Do I need a second battery in the back? XS\Kinetik?

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[09civic 5,000+ posts]

you shouldn't....all i can think of is the grounds

 

[ColterDC 10+ year member]

What he said ^^^

Definately a bad ground somewhere.

 

[wickedwitt 10+ year member]

you shouldn't....all i can think of is the grounds

Something along these lines. You've got plenty of current, apparently have a bad connection. The only other option is your alt is bad, or isn't putting out what it says it is.

 

[wickedwitt 10+ year member]

you shouldn't....all i can think of is the grounds

Something along these lines. You've got plenty of current, apparently have a bad connection. The only other option is your alt is bad, or isn't putting out what it says it is.

 

[dgaf 10+ year member]

I got big 3 done.

I even ran a 4 gauge wire from my battery negative to a ground block.

The ground block is then attached to a bolt that used to hold down the back seats seat-belt.

I had the ground attached to the area you can see that was sanded off, it was attached with self tappers, that was before I got the idea to use the bolt there.

I had an issue with my last install having a bad ground, so I went through all the precautions to make sure it wasn't an issue this time.

 

[ColterDC 10+ year member]

Has it always dimmed or did it start after the big 3 or after you changed alternators?

 

[dgaf 10+ year member]

first system in this truck.

had the big 3 done and alt in before the subs\amp went in.

 

[Epic0318 10+ year member]

if its a 280 amp alt wouldnt you need 2 runs of 0awg to your bat? and i think a second bat would help

 

[ColterDC 10+ year member]

Thought a 1/0 gauge could handle 350amps?

I think a multi meter and some testing might be needed.

 

[dgaf 10+ year member]

if its a 280 amp alt wouldnt you need 2 runs of 0awg to your bat? and i think a second bat would help

didn't think a second run from alt to battery was needed since it's only powering a 2500w amp.

anyone else recommend adding another 1/0 run from battery to alt?

 

[Epic0318 10+ year member]

well since 0 awg can is rated to handle 250 amps. but idk thats my guess that it might help but i also think a bigger bat is in order

 

[sacsking916 5,000+ posts]

add an extra couple runs of postive and negative.

 

[dgaf 10+ year member]

add an extra couple runs of postive and negative.

runs from where to where?

alt to battery?

ground block to battery?

 

[sacsking916 5,000+ posts]

runs from where to where?alt to battery?

ground block to battery?

you probably would be safe to add an extra battery in the back. and add 1 run from your alt to battery. and if you choose to add another bat then do 2 runs postive and negative