Cranking battery goes dead

[ejh]

I have a 1995 Johnson 130 HP. The cranking battery would not keep a charge so I bought a new one, same problem. I took boat to the marine repair shop, the repairman checked out the charging system and said he only found a loose ground wire on the switch. Two days later the battery was dead again. He told me to disconnect the positive cable and other wires to the positive and check for sparks when touching wires to positive post. No sparks. I put my multimeter on one of the red wires, about a 10GA. wire and I read 1.0 on the 20ma scale. It appears some current is flowing how do I find out what is causing the battery to drain. Thanks, Ed

 

[Xcusme]

Re: Cranking battery goes dead

Ejh,<br />Welcome to the forum!<br /><br />Replace the wires as they were originally connected. Setup your meter to read DC volts.<br />Place the Red meter lead to the positive battery post, Black meter lead to the negative post. You should read battery voltage. Start motor and again read the voltage. If the charge circuit is OK, you should see a charge voltage in the 13.8-14 volt range. This verifies that the charge circuits are working along with the rectifier.<br /><br />To test for a current leak while the motor is off, remove the 10 gauge wire from the positive post. Setup your meter to read high Amps. Place the Red meter lead on the positive battery post, the Black meter lead to the 10 gauge wire. If you register any current flow (amps), that's the rate of battery discharge. Perhaps a wire is partially shorted to ground (high resistance short)causing the current flow, there shouldn't be any current flow with the motor off. Any electrical device can be the cause of this current flow, lights, depth sounder etc. Find the cause of the current flow and turn it off. The meter should now read zero amps.

 

[Stratosfied]

Re: Cranking battery goes dead

Ejh, I have a radio in my boat that has a hot wire which has to be wired to the ignition switch in order to keep the battery from premature draining. My thought for you is, are you sure that all the electronics are off and that they aren't draining the battery? Just a thought.