Another solution to the positive ground car and modern negative
ground stereos incompatability is to add a smaller additional
battery just to power the radio (assuming you don't
buy a power hog radio/stereo). You can put a small motorcycle
battery in the trunk and wire it to a DPDT switch so
it can be cut over to be charged by the regular
electrical system or to switch it to directly power the negative
ground radio/stereo. With that arrangement you can't play the radio when you
charge the battery, but for long trips, that's probably no big deal.
Here's how it can be done:
A DPDT switch has 6 contacts or connections (get one from Radio Shack)
You want one with several amps rating and it is nice should have a center-off
position. Use of the switch then would be as follows:
Position 1 Center position Position 2
Radio Powered - OFF (Battery disconnected) - Charge Battery
Positive lead to
motorcycle battery
Positive Lead | Connect to car's frame
from Radio | (i.e. positive ground)
------------------O O O------------------
Radio On OFF Motorcycle Battery Charging
------------------O O O------------------
Negative lead | Connect to car's hot
to Radio | lead (i.e. negative)
Negative side of
Motorcycle battery
The switch can be mounted under the dash. Use of this set-up eliminates
concerns of
the radio shorting to ground because when the radio is on (Position 1),
there's no connectivity at all between the radio circuit and the
car's internal battery/charging system. When the motorcycle
battery is being charged (Pos 2), it is in parrallel with the regular
car battery so there is no electrical difference between grounds.
Hope this helps.
Cheers,
Bill Sohl Budd Lake, NJ billsohl@planet.net
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Visit the Mount Olive Township Republican Party Home page at:
http://www.cns-nj.com/mtolive
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