battery post arcing

I have really bad battery post sparking/arching

one day my battery died in parking lot, wouldn't jump, went back home to swap batteries in
got a nice lil light show, one wire on harness caught fire..
needless to say I've ended up replacing everything in the electrical system in steps, voltage regulator, harness/battery cables/terminals, alternator ...problem still persists..

I know a lil spark is normal to complete the circuit if something like radio or w/e is drawing current, but this is beyond normal..
and no, the battery is not hooked up wrong, grounds are good.

Could it actually be something else in my car shorting and causing this thats not related to the charging system? like cd player or something else?

Thanks in advance

 

How large of arc are we talking??? With all accessories off there should be no arc... Any memory circuit in a modern stereo should only draw maybe 15ma(.015 amp), not enough to create a arc...

Assuming there is a problem, you need to isolate the different circuits, if your fuse block unplugs I'd try that first...

 

Could be anything at this point. Connect an amp-meter between the + cable and + terminal on the battery and see exactly what your amp draw is. That could narrow it down to an accessory or a direct short. Pull all the fuses and try connecting the + cable again. If it still arcs, you have a grounded wire somewhere. If not, plug one fuse in at a time (with battery disconnected, repeat step one) until you find the source of your draw...

 

I am surprised fuses are not blowing first.

 

chances are you will blow the fuse in an amp meter. they are usually rated at 10 amps. if you throwing big arch and draining the battery fast, you could have more than the 10 amp draw. sense you dont need to measure the draw, put a test light in between the battery post can cable. i can be on either the positive or negative. try pulling all the fuses before you hook up the test light. if the light lights up then you know its nothing after the fuse block. that only leaves any aftermarket wiring, the alternator, or starter circuits. if the light is off with all the fuses out, put one fuse in at a time till the light turns on. then you check all the components on that fuse circuit.

 

I thought everybody had one of these "leftovers" kicking around in an old toolbox, no fuses here...

 

that will work, but nope i dont have one. have been parked by one of the aftermarket ones failing in a car i had.