I am wiring my dual fans on my 65 Chevelle, stock external regulator, 327. I bought the wiring kit which includes relays. It is all wired except for the fuse holder which has 2 wires. It says, " Connects to + power supply and should be located within 12" of the battery." It does not indicate which wire as they are both the same color (pink). My question is, what is a " + power supply" ? Is this the battery junction box behind the battery on the rad. support? Thanks for your help.

Oh yeah, the fan harness was purchased from the guys I got my Spal fans from. The harness company is called "Northern" part # Z40078.

The distribution point behind the battery will work fine. Connect one end of the fuse holder to the distribution point and the other to the positive side of the harness.

You are potentially "playing" with fire if you expect the stock wiring harness to handle the additional load of the two fans.

If you are still using the stock alternator it may not supply enough power for everything.

The stock alternator in a 65 is rated at 35 amps. It can be rebuilt to supply about 70.

If you do that, and upgrade the alternator wire to the horn relay and from the horn relay to the "junction box" on the radiator support and from there to the battery you will be ok.
Install a 10 gauge wire in parallel with the existing wire and you will be ok.