Begin by disconnecting the car battery, taking note of any required precautions suggested
by the vehicle manufacturer such as alarm or radio codes, or on board computer or AGM
battery requirements.
For vehicles with front mounted batteries find a suitable point on the firewall/bulkhead to
run the power wire through. Where the cable passes through the metal it is absolutely vital
that a rubber grommet be fitted to prevent the cable from chafing through the insulation as
this would be a major fire risk. The positive wire needs to go to the + positive terminal on
the battery. A fuse of appropriate size to protect the cable needs to be fitted in line no more
than 18” from the battery.
Once you have the power cable in the car, run it back to the bass box. When you do this, be
aware that you will need to run the remote turn on cable and the RCA signal cable from the
head unit back to the amp too. If you intend to use the high level speaker inputs rather
than the RCA cable then at this point run these in too by tapping into the cables from one
left and one right speaker. Ensure that your taps are well insulated and safe. Our Power 8.2
Active box has the facility to use “auto turn on” which senses the music on the cables and
switches the unit on and off as appropriate. In this case you could choose not to run the
remote switching lead. Note that the auto switching function only works with the high level
inputs – not the RCA inputs.
If the wires you are running have to run over or go alongside other looms of the car, try to
cross them at right angles to avoid unwanted interference in the signal, and try not to run
them parallel with other cables either. If you can, run the power and the signal cables down
opposite sides of the car. This isn’t essential but if you do get any interference once the job
is complete the first thing to look at will be separating these wires so if you can do it first it
makes a lot of sense!
The absolutely most important aspect of the power install is the earth wire. This wants to
be very securely bolted to the chassis of the car. We recommend drilling a hole (take care
not to drill through your spare tyre, brake lines or anything else) in the boot floor and sand
off any paint to the bare metal where the wire will be connected. A bad earth is a very
common flaw in installation and can cause a number of headaches later down the line so be
sure to take care in doing this. Do not use a self tapping screw to secure the earth down, as
it will probably soon come loose and impair performance. Other common disasters include
trying to earth to rear light mounting bolts, boot lock mountings and other ways to “trap”
the cable in the hope you might get a good earth. For every volt the amplifier doesn’t see it
requires twice the power to create the same output which means poor performance and a
possible broken amplifier. Once the work is complete neatly repaint the over the finished
bolted connector and chassis of the car with some primer to prevent corrosion.
