Jensen POWERPLUS 420 - Manual (Page 6)

PowerPlus Amplifiers
6
Ground Terminal (GND)
Make the ground lead as short as possible, leaving enough length to complete
the installation and to allow for any service that may be needed at a later date.
To ensure a good ground, scrape away any paint or undercoating to expose
bare metal. Use a "ring" terminal of the proper gauge and an "outside star
washer" (between the chassis and ring terminal) when making your ground
connection. Although you’ve scraped away the paint to expose bare metal, the
outside star washer will help to "bite into" the chassis for a tight, secure
ground.
Replacement Fuse Requirements (FUSE)
Model Quantity Amps Type
420 2 15 ATO
480 2 25 ATO
900 3 30 ATO
1150 4 30 ATO
1302 1 60A MAXI
1304 1 80A MAXI
Drill hole in chassis sheet metal.