How do i wire this to the stock harness for my s13..the s13 has 2 wires and the altima fan has four..is there 2 speeds?

 

The easiest way to find out is to take the wires, strip them and carefully test them on your battery terminals. Obviously, look for the black to be the ground and go from there.

I always wire up electric fans with a HD relay (one that is spec'd out for high-powered fog lights) and use 12-14 gauge wire. A 30 amp fuse should hold just fine. Personally, I like to have the fan come on with the key but some others have it come on with a switch or a thermostatic switch. It's personal preference really.

Hope that helped out a bit.

 

Alright cool..thanks!