wire size on relay

[kglowacky]

setting up my relays to the following .

Fans - currently the fans have 12-10 gauge wires coming from it. The fan assembly came off a 2005 Chrysler . I bought 30 amp relays. They came with 14 gauge wire. Do I need to re wire these relays with 12 gauge wire?? If so do I need to rewire the three wires to the bigger gauge and leave the switch wire at the smaller gauge as it will be connected to the ecm small gauge wire.