I have a 95 civic ex and recently the fuse for the instrument light, tail lights, and license plate light blows. It says 10 amps so I replaced it and it blew, I put a 15 and it blew,20 it blew, right now it has a 30 amp fuse and is working but why is this happening.

 

Circuit is being overloaded? That's why they have amps listed. Right now you are allowing more amps to be passed through that circuit than there should be. You have to find out where the short is occurring. (I hope I explained that correctly)

 

will it hurt anything to run the 30 amp fuse. this is my dd and I drive a lot at night but I cant afford a tail light ticket. ill see if I can find a short somewhere.

 

You're allowing more than 20 amps to run through a circuit meant for a maximum of 10. You're just asking to fry something. Find the short and fix it or there is a good chance you will run into more problems.

 

Yes putting a 30A fuse into a 10A socket can very well be damaging. If a water pipe was only rated for 10 psi would you put 30 psi through it and walk by it? With more current you are overloading the wires for one thing, which creates a fire hazard when they completely melt. Also if the "short" is down stream of any lights, you will ruin those very quickly because a lot more current is flowing through, superheating the filament.

Since your system works with 30A then there is enough resistance in the circuit for everything to work, yet a significant enough contact to "ground" for 20A+ to flow, which is a big problem. It is probably on a light fixture, or where a screw went through the harness. If not then you have a lot of tracing to do....

 

It's a fire risk to install anything other than a 10A fuse.

Did you recently install a new stereo?

 

no its had an aftermarket stereo for a while.

 

If it wasnt installed properly, connections can easily break, or work free. I would start with all those connections behind the stereo