Join Date: Sep 2006
Thanked 11 Times in 11 Posts
Rep Power: 10
If the battery panel was disconnected prior to the incident, it will have known nothing about it.
The kill line simply cuts off the fuel delivery to the injectors and the motor stops. A diesel engine will carry on running, as long as it is getting fuel.
On a gasoline engine, the key turned to off will kill the spark, and it stops.
When you turned the key off with the engine running, you will have disabled all the sub-systems that are fed by the ingnition power supply.....rev counter, engine temp guage, and I suspect you will have disabled (not damaged) your alternator too.... it depends on the set-up. I really don't think you will have taken out the alternator diodes... the classical way to blow those is to disconnect the battery master switch with the alternator charging, and that is not what you have done !!!! I have done that a few times... someone's foot would hit the ignition key with the engine running. On my boat, it just interrupts the charging, and the charging ammeter betrays it.
Start the motor, and put a wee multimeter across the battery terminals to see if you are charging... it should read about 14 V.... never 12 V. If you are charging, then your diodes will be fine. A multimeter is about Ł15 and it's a classic diagnostic tool for your ship.
Your diodes rectify the AC output from your alternator to DC for your battery charging and the electrical loads. They are normally in the alternator, but not always.
If you get into this stuff you will find it interesting. It is not that difficult if you get into it... at least get into the basics. You will find an alternator to be an extremely simple and absurdly clever device, for example.... reliable as sin, and easy to maintain.