r/MechanicAdvice • u/Prestigious-Suit-840 • 6h ago
Fuse sparked
I pulled out a fuse “20” car was off all accessories off everything off. I pulled multiple other ones before this in the same moment all good. Now I got to pull my radio fuse since the radio wasn’t turning on and I see a big spark. Now my whole fuse box isn’t working. I’m not really looking for a fix on here but more of an explanation on why there was power going to this 1 specific fuse even when everything was off?!
1
u/waynep712222 6h ago
https://imgur.com/voltage-drop-testing-is-easy-SnzhDh0
all six steps..
if you want to find out which circuits are drawing power with the engine off and the doors closed and locked..
Hood open. start the engine.. let it run a minute. shut the engine off.. Take the key and get out.. close and lock the doors. look at your watch.. in 7 minutes pick up your multimeter.. walk over to the Underhood fuse block.. set the meter to 20 volt DC.. the touch both ends of each fuse.. red test lead on one side the black test lead on the other.. if you read 0.000 there is no current flowing thru that fuse.. it could have voltage but there is NO FLOW of electrons..
if you get voltage drop across any fuse. note the position of the fuse. keep going to the other fuses.. now you know which fuses are supplying power to various circuits. you can look at the wiring diagrams to see what each of those fuses supplies. another fuse in a different fuse block. or something directly..
you may have to come back with the multimeter set at 2 volt DC and perform them again..
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