bengaltiger14
New member
I have a Mercruiser 5.0L MPI Bravo 3. This past Saturday, I killed my batteries while playing music all day. I got a jump and got the boat started. I noticed when I took off that the boat seemed to lack the normal power. About half way back to my destination, I noticed that the battery gauge was acting erratically (going up to 16V and then back down to 12/13V). As soon I got near to dock to pull the boat onto the trailer, the boat shutoff. I then had no power to ignition or dash switches. Boat won't turn over at all. Nothing happens at all when the ignition switch is turned. No low oil pressure alarms or anything. .
Purchased and installed a brand new battery. When key is in the 'OFF' position, I have voltage readings as follows: 11.25V at both sides of 50A circuit breaker, 11.25V at the red/purple wire at slave solenoid and 11.25V at the Orange wire on the alternator. 10.8V at the battery connection on ignition key switch.
In the 'RUN' position, I am reading around 2.25V at all locations mentioned above.
However, if I disconnect the red/purple and purple connector from the alternator, I read a full 12.6V at all of the locations mentioned above when switch is in 'OFF' and around 2.6V while in 'RUN'.
Swapped out the alternator and ignition switch. Problems still exist. Still reading 2.25V at 'B', 'I', and 'A' when switch is in RUN and reading 0V at B, I, A and S when in start.
One interesting thing to note. While in RUN and reading 2.25V at the key switch, I flipped the kill switch to the OFF position and the voltage spiked up to around 8.4V at B, I and A.
Thoughts or suggestions please?
Purchased and installed a brand new battery. When key is in the 'OFF' position, I have voltage readings as follows: 11.25V at both sides of 50A circuit breaker, 11.25V at the red/purple wire at slave solenoid and 11.25V at the Orange wire on the alternator. 10.8V at the battery connection on ignition key switch.
In the 'RUN' position, I am reading around 2.25V at all locations mentioned above.
However, if I disconnect the red/purple and purple connector from the alternator, I read a full 12.6V at all of the locations mentioned above when switch is in 'OFF' and around 2.6V while in 'RUN'.
Swapped out the alternator and ignition switch. Problems still exist. Still reading 2.25V at 'B', 'I', and 'A' when switch is in RUN and reading 0V at B, I, A and S when in start.
One interesting thing to note. While in RUN and reading 2.25V at the key switch, I flipped the kill switch to the OFF position and the voltage spiked up to around 8.4V at B, I and A.
Thoughts or suggestions please?