Completely dead electrical system

[pearldrumbum]

91 explorer 4.0, 5spd, 4x4...


Last week I was driving and had a battery light come on just for a minute and then go away so i didnt think anything of it. Then I had the battery die on me the next day (like there was some kind of parasitic drain), but i had to go out of town for about 6 days so i figured i would deal with it when i came back. Came back today and the battery was dead. I still didnt think much of it, i just threw it on the charger and took a different car for the day.

I came home, the battery tested out fine, so i put it back in and tried to start the car. It turned over for a second and then i heard a pop and nothing. Everything went dead, no lights, radio, dome light... nothin.

Any ideas where I should start looking to fix this? I checked all the big fuses by the batter and everything is fine there.

I installed a new amp and sub about a month ago... but everything was fine until last week, so i dont see that being the problem.

thanks!

 

[BRUTUS_T_HOG]

are you sure your battery cables are on tight and clean?

check the battery cables for broken spots and fraying and make sure everything is clean and tight.

there is a 150-175Amp mega fuse but that protects the alternator where this problem might have started.

do you know if the alternator is charging ok?

 

[pearldrumbum]

i checked the cables, they look good. (my multimeter is fried so I couldnt do an actual continuity test), but they look good to me, not even any corrosion.

I dont know for sure if the alternator is working, I'll take it off and have it tested in the morning.

Where is this mega fuse located?

 

[BRUTUS_T_HOG]

the megafuse is inline between the alternator output cable and the positive battery cable.

it will be under a cover in the fuse box and screws in using 2 screws

 

[strvger]

also, don't forget to check all the grounds. more times than not, it seems to be a ground somewhere that causes the problem. good luck.