Slow drain on battery

[The RedheadPimp]

Alright so here is what happened. I was driving down the highway a few days ago and the battery died while driving cause the car to shut off on me no matter how much i put the throttle to the floor. I replaced the battery about 16 months ago so i figured it was still good. I went ahead and bought a 100% new alternator and installed it, charged the battery. Everything seemed fine so i decided to take it out and it died after about 90 min of driving. I thought maybe my ground from the battery was bad so i went and replaced the terminal and wire and wet sanded the spot where the terminal wire mounts onto the engine and replaced the ground from the engine to the front frame. I am still having problems and it is quite frustrating. I took the car down to a local advance auto parts and they hooked a machine up to check my system. The reader came back with results saying that the battery was good and the alternator was good. It says i have a small drain tho, o.o2 A. I am running 2 amps to power my 4 12" subs in the car but have had them in the car for well over a year now and this is the first problem i have had. Both amps are connected directly to the battery with a fuse in the line. I am at a point where I dont know what to do. Any suggestions?

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[electric130]

check the big power fuse between the alternator and the battery. should be around 80A i think.

[gearbox]

it could be a loose power cable from alternator to the battery. are you reading around 14v when the car is running and you measure the voltage at the battery terminals?

[The RedheadPimp]

I fuse is fine. It was the first thing i checked. Should i replace it even though its still good? I will double check the cable but it is reading 14v when the car is runnning.

[electric130]

take it to autozone and have them check the charging system. it's free.

[The RedheadPimp]

I took it to autozone and they were no more help than advance. i am starting to think that i may have just bought a faulty alternator that is still reading as good for some reason. I had a few buddies look at the car and said the same thing. Or it could be from my spark plug coils. I am really not sure what to do at this point though.

[gearbox]

are you sure they are testing the alternator properly? because it may read "good" as far as volts, but the amp output could be way low like 20-30 amp instead of 70. that would cause slow drain of the battery while driving cause there is not enough power to run the car and charge the battery. i used to work for advance and its real easy to misdiagnose a bad alternator if you dont know the machine well.