Here is the procedure for the cable that goes from the battery to the under hood fusebox. it should be obvious where to go to the alternator from here
OK, I have the service manual here sitting in front of me. It appears to be pretty straight forward to me. If you have basic wire routing and mechanical ability, it should be no problem. As you probably know, the battery is located under the rear seat cushion.
Pull up on the rear seat cushion to remove it ( you probably did this to install your speakers)
Disconnect negative, THEN positive battery cables.
On the passenger side of the vehicle, you will need to pull the door sills/carpet retainers up in order to peel back the carpet for access to the power cable.
You will also need to loosen and possible remove the center pillar cover. All three of these parts simply come off with a tug outward and are held in with bodyclips.
Next, the Insulator panel needs to be removed. This is the piece that is behind the glovebox and above the passenger footwell that covers up the under dash area. There will be fasteners on the back edge of this piece and a couple small clip retainers that will need a slight pry to get loose. These will be toward the front/sides.
From here, you should have all of the battery wire exposed that is in tehe passenger compartment.
There will be a few retainers that hold the cable in place.
unseat the power wire grommet on the firewall
remove the nut on the underhood fusebox to free the front portion of the cable and ensure there are no more retaining locations. The cable should now be free from the car.
2002 Nissan Maxima SE - 15.143 at 91.74mph - Short Ram Intake - 2* Timing Advance- Tein Coilovers - Front Strut Brace
00-01 SE Tails - Smoked side markers - Painted and Cleared Headlights - Weathertech rainguards - Tinted to 27% - CF Gauge Trim
Stereo: Eclipse CD8445 - Kenwood KAC7201 - Kenwood KAC-729s - Cadence Components - 2x MB Quart Reference 12s
2000 Bonneville SE - Retired