I have a 94 civic si, I bought a 14" slim fan for my car, when reading the instructions it said that the fan needs 24A, the problem is that the cars stock fan only uses 15A, would that extra amps melt my wires?

 

Yes it would, if it did not blow a fuse further on down the line.
15A vs 24A is a hell of a difference.

You could run a new cable from the battery through a fuse, and then through a relay (to switch it on and off) and then to the new fan itself.

Switch the coil side of the relay with the existing fan wiring, and it will work sweet as.

Also this will allow you to run both the stock fan, and the new fan together.

 

it depends what gauge wiring sometime the stock gauge is large enouhg for the bigger amperage

 

Im not sure what gauge it is, let me see if I can find some info on that, thanks for the replys