Self starting diesel

[Loon]

. On Sunday a dock mate came by the boathouse, heard the motor running and called us. We went down, found it was so, tried the kill button with no luck, turned it off at the engine. We found all batteries dead (kill button in-op). Assuming vandals, we went that way for a while but no forced entry and nothing disturbed.
The answer. I didn't think it was possible but it can happen. I changed out the coolant on the engines and evidently spilled enough (less than a cup) on the starter on Thursday. After seeping and evaporating(accreting) for three days the starter shorted, started the engine, drained ALL the batteries (now I will isolate them). The starter rebuild specialist said this is the second time he had seen this in over 30 years in the business. The only good news is the batteries were almost 7 years old and needed replacement. I'm also looking at adding a rubber shield over the starters.
Forwarned is forearmed
Loon

 

[jleonard]

I experienced this on a diesel backhoe. It was set up in our factory to do some excavating work and one quiet Saturday it started up on its own. It was on its chocks so harm was done.
The starter relay had shorted out. It was located near the battery.

On another occasion my 70 Dodge Dart tried to start on its own. It was in my driveway and in reverse (manual trans) and it stared backing up the driveway under the starter power. I got to it before it started and disconnected the battery. Again it was the relay that shorted out, located under the battery box (bad place).

 

[High Wire]

what engine model?

 

[Loon]

Self start

Perkins 6.354. 1983ish

 

[kchace]

This is not the only fault that can cause serious issues with fully energized systems. If you have battery switches on the engines (which I think you should) it is safer to turn them off when away from the boat. If you need to leave the engine battery switches on when away to keep other things like automatic bilge pumps active, then the wiring is set up incorrectly.

Ken

 

[Loon]

Self starter

I have the switches and NOW I'm smart enough to use them!

 

[koliver]

I have seen this happen. The culprit was the start switch on the upper deck. It was one of those push button switches with a rubber cover. The rubber split, allowed water in and shorted out, running the starter. This happened while the engine was running, so burned up the starter, but otherwise did no harm.

 

[FF]

"If you need to leave the engine battery switches on when away to keep other things like automatic bilge pumps active, then the wiring is set up incorrectly."

The simplest is a 1-2 - Both ,Off swithc just for the engine start corcuit.

And a second 1-2- Both -OFF just to handle the house loads.

Both switches in BOTH when cruising , after engine stop , the engine goes OFF and the house selects the battery bank desired.

KISS

 

[Mule]

FF nails it again.