Q. I read CA&E every month. I own a four-door '92 Ford Explorer and have two 10" Kenwood Tornado series subwoofers with a 280-watt 2-channel MTX RT2200 along with a 1-farad capacitor. I plan on upgrading by adding another MTX RT2200 and have each amp bridged to one subwoofer. The problem is my lights were dimming so I added a capacitor and it helps a little, but with the A/C or heat on in addition to the headlights and radio, too much power is drained. Should I get a new alternator?
Thanks,
Ian Charles
Q. I've a '97 Honda Prelude and quite a few audio components installed in it. I've been wanting to put a second Optima YellowTop in the trunk to help combat the lights dimming. I was wondering if there's any special way to do that or if I need some special relays or anything of that nature?
Thanks for the help,
Nate Van Heel
Q. I hear there's a component that stops your car's lights from dimming every time the bass hits in the car. I believe it's a capacitor. Can you explain how to install and charge the capacitor?
Thank you for your time,
Aric Angel
A. It is a common idea that adding batteries is the answer to a wide variety of problems, but it often causes more problems than it cures. In an economy-based vehicle like many Asian imports, the electrical system isn't built to handle much more than the stock loads built in by the manufacturer. By using an alternator that is only just adequate, the carmaker is able to deliver a great car at a great price. We're so used to looking for the lowest price that manufacturers will do anything to achieve a lower price point. In the end, we get what we asked for but only in terms of a cheap price tag.
Ben and Ian, you are both at the point of needing an alternator upgrade. If measurements indicate that you can't get it up over 13 volts, an aftermarket alternator is the way to fix that problem. In this way you're keeping the voltage sufficient to keep the battery charged and supply your growing system.
By adding a second battery, you're increasing the current available when bass hits, but batteries are notoriously slow to give up the power when you want it. In addition, the battery is viewed by the alternator as another load, which takes the total load beyond the capacity of the alternator. Now your system will have trouble charging both batteries unless you upgrade the alternator at the same time.
You'll also need either a battery isolator system or a contactor that will keep the batteries from killing each other off when the car is parked. This is another complexity in addition to a new aftermarket high-output alternator. At the end of the expense, your lights will still dim somewhat on bass notes.