CD Player Power

Ran into something with a CD player that is new to me at least, so thought I would point it out to others.

In the past, most CD decks that I have installed had a power lead which would be switched from the ignition, and another wire which was for backup of the memory. The electrical load was carried on the power lead, and the backup used just a small amount of power.

Newer decks are now coming with an ACC (accessory) lead and a BATT(battery) lead. Using the same logic, you would think that power is on the ACC lead, and BATT is simply memory backup, same load requirements. YOu would wire the ACC to the RED/WHITE lead in the console, and hook the BATT up to power. (I simply put another connector on the purple wire for the courtesy lamp and wired it that way. Made sense.)

Incorrect. Now, the deck obtains its power on the BATT lead, and the ACC lead simply turns on/off the deck, it has no real power requirement, almost a reverse of previous operation. I found this out by accident, as I was reconnecting some speaker wires, had disconnected the BATT lead, and tried to turn the unit on......nothing until the BATT lead was connected.

Talked with middle kid who is involved in making cars that shake paint off, and he confirmed this. He didn't think anything about it, since they always run power to the battery for the 30 JigaWatt amplidiers they run. He offered me some heavy duty power cable for my B with "monster" fuses, I think the welder has smaller cable.

Thought I would point this out to others.......

I ran into the same thing a couple years ago - except the schematics were very VERY vague on the subject. The premise is you no longer run high-current (relative term) through the ignition switch or relay, it comes directly from the battery and the switched side is very low current.

The Kenwood I installed in my MGB uses the "old" method, but just as a precaution against some of the original wiring and connectors in the MG, I used a relay to duplicate the setup you described. I built a wiring harness so everything on the car side has a special plug so there's no additional hardwiring if I change anything in the car, but now the higher-current feedline gets switched on/off via a 30-amp relay nicely isolating the radio from everything but the battery.

My original reason for doing all that was because I intended on putting a low-power amplifier up front but haven't done it yet.