I killed my Volvo Penta AQ120B / 270 Bahama

[MikeCaldwell]

I got this boat after it was sitting in a garage in LA for 30 years since 1980, Volvo Penta AQ120B / 270 Bahama with 20 hours. I got NEW Tires, impeller replaced, anti freeze, thermostat and oil changes.I went over things (I built my own motocross bike Honda 450 , work on cars and computers FYI) Love the boat, lots of great times al ready. I got a trolling motor and Garmins 70s and dual battery setup. Been to lakes, Rivers in Sacramento and SF bay.
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OK, about 2 trips out we lost the wire to start it, replace.
Next, after a couple more trips out we lost Start, replaced, worked great
Last Trip, I was tired of the batteries going down NOT Charging so new Alternator and here we go.
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Last 2 days Each night after work I was working on it in and had to change a wire with 40 fuse all was good
This alternator had an extra post (assuming Field+) so I ran it to 12v, the other regular B+ and B- and Negative
My first DONT DO IT IDIOT was hooking up that FIELD+ when I didn't have it on the original.
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NOW The Scary Part, I started it, running, everything normal, I give it a little gas and look at voltage meter it is off the chart all the way to the top 19V+
and then I hear a POP, engine still going I shut it down, not quick enough.
DEAD, I have voltage to battery switch on both batterys, 12v but ,battery 1 is low. I tried to jump starter and NOTHING! Turn key switch NO lights, nothing.
I kill my boat, help! What can be in a position to completely block the power? What could have popped? I change the relay to starter I had one (4-prong)
I get 12v TO 40amp breaker but nothing out so I applied 12V with CarJumper on other side, nothing! What gets me NOTHING when keys is ON, panel black, nothing. HELP!

 

[MikeCaldwell]

FYI It was a LOUD POP that came from behind me so I assume it was something around the engine

 

[Scott Danforth]

probably took out something in the ignition.

start troubleshooting. in this case, use your nose. when you come to something that smells like burned electrical, there you go.

 

[MikeCaldwell]

Problem solved, 40AMP Circuit breaker off the starter solenoid to the Trim\Tilt (Only breaker was to old and slow to break so it was the LOUD POP. Most likely from me adding the Field+ on the ALTernator to Starter Solenoid. I found it talking to someone buying my pool, when I stuck a screw driver across the breaker everything lit up. So I skipped the breaker for testing , dropped the Field+ connection and I got it running on both batteries at 14V. Great thing, I am redoing all Fuses to new INLINE Breakers all 3 - 50,40,20 mounted on a board and getting rid of the fuses. Fuses are a hassle, you cant see when they blow and you have to keep buying new ones. Now I can just reset and it's nice and clean with 8 AGW and less chance of future problems, Coil replaced and next a Conversion on the Distributor to electronic.