2007 Fit Base, this is in the fuse box under the dashboard.
7 pins, isn't connected to anything
What's this harness for?

One of the wires has constant on 12V "+" that I want to tap into, but I'd like to understand what is it first.

TIA!

 

You have a base fit...Does it have keyless entry?

Dealer installed keyless entry wiring harness has a 7 pin connector with a dummy cover.
If the owner purchases the accessory security system to go along with that keyless entry, one of its connections is to that green 7 pin connector. (If you need to see the install instructions for the keyless entry with simple pictures of the layout, go to estore.honda.com)

In that 7 pin connector:
Black is ground
White/red is +12v constant power but it's coming through a 2 amp fuse in the keyless entry harness.
Yellow, +12v with key on, also comes through a 2 amp fuse in the keyless entry harness.
The rest are for the security system functions.

Because the connector you found has power that comes through a tiny 2 amp fuse, Whatever you are trying to hook up better be needing less than one amp of power.

If you need more amps than that, start following that harness until you reach the 2 fuse holders built into the keyless entry accessory harness.
The constant power 2A fuse gets its power from a 20A fuse in the dash box in position #20 (probably labeled 'Honda accessory' or similar).
Both sides of the constant power 2a fuse are the same colors (white/red) Remove 2a fuse and probe for voltage to determine which wire is between the dash fusebox and the 2A fuse, and tap in?


If position #19 in the dash fuse box is open, one side of that slot is constant power as well.
Dash fusebox fuse positions 18, 19, 20, 21 all share one 30a fuse in the engine compartment fuse box.

 

You're right! Base fit, dealer installed keyless entry, no security unit.

And yes I need more power than 1-2 amps, that's exactly why I wanted to know what circuit is that. Thanks for the suggestions I'll try that tonight.