wrote in message
oups.com...

I tried to start it, but it appears the battery is dead. I
tried to
jump start it with the jumper, but it would not start. The
voltmeter
on the dash indicates 0 bolts. Usually when you hook up the
jumper
cables, the voltmeter will jump to 12 volts as soon as the wires
are
connected.

I replaced the battery - same problem. I sanded the connectors
to
remove any oxidation - made no difference.

Turning the key, nothing either.

The stereo turns on and plays music, but the marine radio will
not. I
checked all the fuses under the dash and they all seem ok.

I don't know your boat, but my first checks would be:

1. Check and clean *all* high amperage circuit connections -
that includes the earth returns, often forgotten.

2. When you select 'start', listen for the solenoid switch to
click. If it doesn't click, clean *all* the low amperage solenoid
connections, including the earth returns.

3. If these don't work, get your portable multimeter out of the
attic. Lift the positive terminal off the battery and check the
circuit resistance through the starter motor, then through the
solenoid. Both should show just a few ohms. If they don't, there's
a break in the motor/solenoid circuit. If they're OK -

4. Check the resistance through the circuits from the battery
terminals - with the switch made.

After this, you should have narrowed the fault down to either a
line break, or a high resistance joint, and you'd know whether
it's in the solenoid circuit or the starter circuit.

Best of luck!
--
JimB
http://www.jimbaerselman.f2s.com/
Describing some Greek and Spanish cruising areas

4. Check the resistance from further up the circuit - nearer the
battery and trace