Electrical gremlins

What amp fuse is inline?
Volts don't mean squat really when it comes to fuses, amps do and if you are running less than a 30 it doesn't surprise me that it blows.
Main fuses in some cars are 50 and 60 amp.

I think what is happening is when you start the car it draws the battery down a little and when the car starts it tries to replace that used power from the battery and blows the fuse because it's too much amps for the fuse to carry.
ESPECIALLY if it usually only blows on startup and not any other time.

Thanks for your reply. Currently the fuse rating I'm using is 30 amp...It's been running good for the time I said. Only recently started popping the inline fuse. Sometimes on start up...Sometimes it blows when I rev up the engine...Sometimes it don't....I drove it to work..No problem. Reach home turn it off...Wait a couple seconds. Start it and the fuse has blown..Sometimes that doesnt happen...My headlights also stopped working only the parking lights working (thinking that's the switch).