Hi guys,

Thanks for the help. The voltage only drops while the starter is
engaged and it is only for a second or so. Once the engine start, the
voltage is always above 12v.

Thanks,

Walter.


The Lizard wrote in message ...
Walter McCann wrote:
Hi,

Hope someone can help me. When I start my car (Alfa Romeo 156) the
voltage drops to below 10v. This causes the radio to reset itself -
and an associated interruption. Is there anyway I can stop this
happening?

Have your battery tested. Your system shouldn't drop below 12 volts when
you start. This indicates that there is a problem in your charging
system. Either the battery is bad, or your alternator is no longer
charging.

Otherwise, you can use a very large capactior (100,000 uf) on the main
power wire, with a diode to isolate it from the cars electrical system.
Of couse, you'll get a slight voltage drop across the diode, but luckly
you're going to have to use about 4 diodes in parallel to be able to
handle the current of most decks (standard power diodes are about 3
amps), and this is going to reduce your voltage drop.

But fix the car before you start rigging ****.