If I have a blown fuse can that cause my battery to drain? Or is this a misconception? I am curious of how a blown fuse can drain a battery, any advice and how to check would be helpful. Thanks in advance.

 

When a fuse, "blows", the metal element inside the fuse melts or will even vaporize and causes an open circuit across the fuse. Open circuits theoretically are an infinite resistance. NO current can flow across an infinite resistance, so when a fuse blows, current totally stops flowing in that circuit. You cannot drain a battery in a circuit that has a blown fuse.

 

The only caveat I would add is if you blow the fusable Link between your battery and alternator, you will loose the power/charging action of your alternator, and your battery will drain down in no time(but battery drain only occurs during run time, not just sitting in the driveway).

Since you didn't specify what type of fuse, thought I'd bring this up. Fusable Links are considered to be "fuses", they just carry a whole heck of alot more current than the 5,10,20 AMP mini fuses.....