a 12 gauge power wire directly to the battery for power, NOT the fuse box or factory wiring. These use alot of power and the stock wiring cannot handle it. The speaker wires should be ok since the are A/C voltage and not DC like the power wire. If you have the owners manual for the HU it should tell you this also. You will burn the HU up if continue to use it that way. Also use a new groung wire directly to a good ground in the dash.