Merc 135 - Batt not charging

General Boats and Motors
1

Friend of mine has a 2006 Merc 135 and he is having issues with the battery not charging. He replaced the battery, and when the issue continued he replaced the alternator. He says the battery is still dropping very slowly (.1 every few minutes), running at idle and a little above, but he hasn’t let it drop below 12 volts (think it is around 12.3 currently). Does anyone know what the alternator should be putting out (ie 13-14 volts)to start the troubleshooting? He looked for a in-line fuse between the alternator and the starter silenoid, but didn’t find one. Could a bad starter silenoid cause the battery not to charge? Or the bigger question…is it working properly and should only maintain around 12 volts. Thanks in advance for the help!!

Serial Number on the Merc is 1B533019 in the series 1135D83HY.

2004 Sea-Pro 180CC
2004 Johnson 90

2

Charging voltage should be at least 13.2V

Capt. Larry Teuton
Cracker Built Custom Boats

“Ships are the nearest things to dreams that hands have ever made.” -Robert N. Rose

3

at idle voltage will be a bit less than 13.2, but as you increase rpm voltage should increase to above 13
can you get year and model for the motor
that serial number isn’t coming up in the system
optimax engine have an alternator, the carbed engines have a stator

www.teamcharlestonmarine.com
www.joinrfa.org

4

Thanks for the replies!! It is a 2006 optimax.

2004 Sea-Pro 180CC
2004 Johnson 90