troubleshooting wiring

[mdillon 10+ year member]

i am at work so pics will not be available. i recently toasted my sub amp. it is a mb quart 1200.1D it was an ebay perchase so first i assumed it was a "b" stock amp sold as new. now that i am getting ready to buy another amp, i want to make sure that my wiring is ok so i dont go 2 for 2.

1. up front is stock battery, 95 amp isolator approx. 18 inches from alt. big 3 was done with 4 gauge because thats all i had available, no fusing on big3.

2. wire going from isolator to 2nd rear battery is 4 gauge, fused at 100amps. 2nd battery is an exide orbital.

3. power wire coming from 2nd battery to amps are:

a. 8 gauge to the mids/highs amp. amp is fused with 2 20amp fuses.

b. 4 gauge to the sub amp. one 80 amp inline fuse to the sub amp and

2 60 amp fuses on the sub amp.

all amps grounded to the battery with appropriate sized wire, battery grounded to the frame with 4 gauge. 2nd battery reads 13 volts with the car on and off. i do not get any dimming and i believe thats due to the isolator restricting flow?

does this seem like good enough wiring to get the job done? this is a daily setup and is ran on average about 30min to 1 hour everyday.

any help is appreciated

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[jrwalte 10+ year member]

I don't think the isolator prevents the lights from dimming. It's the fact that the alt + second battery can handle the power requirements. If your system demanded too much power from the alt you'd still see your lights dim, because the alt, with or without an isolator, still provides the 14 volts to your lights. And if it can't do that, then your car battery will give your lights 12 volts, causing dimming.

I haven't done a second battery in the trunk, but 13 volts seems low. I get 13.9-14.2 (it matches exactly what my front battery gets) in my trunk. I run 0 guage to a block then 4 guage to 2 amps.

 

[mdillon 10+ year member]

well my dmm doesnt show the thenths it just rounds to solid numbers so its not really accurate. i would estimate on the low side of 13 tho.

edit: is it possible that the 4 gauge is not flowing enough current from the isolator to the 2nd batt?

 

[Atimm693 10+ year member]

An isolator is only really needed if you have to play the system with the car off. So I'd get rid of it.

 

[jrwalte 10+ year member]

I wouldn't think ' not enough current' would cause an amp to toast - just wouldn't perform to the best of it's ability. And as long as the battery isn't being drained you know it's giving 12 volts even if your alt randomly dips below that for any reason.

Is there a reason you fused the wire from the trunk battery to the sub amp and not also your 4 channel?

 

[mdillon 10+ year member]

^^^lack of external fuses during the install. the fuse from the front batt to the 2nd batt is there in case i get in an accident and the wire gets pinched, this way i dont go up in flames while im unconcious. really just for emergency situations that may occur.

i do play the system with the car off sometimes. it also restricts flow from batt to batt so i dont get equalization. people have told me equalization can lessen the life of the batt.