Because there is a short in the system. You need to check:
There seems to be a short to ground in the wiring somewhere.
why does my turn signal light keep burning out and why is the sockets and plastic lens melted.
Unhook the wires on the starter, replace the fuse, turn the ingnition key on as if you were going to start the car. If the fuse does not blow, it is your starter. I just had this problem with a 1996 Dodge Stratus. I replaced the stater and it now works.
Check your starter, my 87 b2000 was doing that. when i hit the brakes,turn signals, etc the CD player would cut off and back on. it was the starter!
Replace turn signal switch. Its grounding when you put turn signals on. I had the same problem and replaced it .Solved issues.
It sounds like maybe your starter might be shorted out - a wire could be touching the casing somewhere or it could be something worn in the starter that is letting something go to ground inside. Unhook starter and try putting the fuse in and turn the key if it blows the fuse in is not the starter.
Dead short Disconnect wiring to these devices to determine what is causing problem
If the 1990 Chevy Lumina is blowing the DIS 10 Amp fuse when the ignition is on, check to make sure that all wires coming from this fuse are grounded properly. Also check to make sure the starter is wired properly. There could also be a loose wire in the dash near the ignition.
you might have grounded out one of the main power wires like a starter wire or your main bat wire to metal and it is causing the fuse to blow because it is sending all that power to whatever the wire grounded to
turn down the gain or the bass
If it's blowing immediately when you turn the key on, there is an electrical short in the system and you are going to need to trace it down. If it blows after several minutes or hours after turning the key on, it appears that your pump is overworking, causing the fuse to get hot and blow. Replace the pump to repair the problem.
You likely have a frayed wire to the stop light.