First sail of the season, I inadvertently shut down the engine on my Catalina 28 by the ignition key. Since then, without the key in the ignition, the minute I turn on my batteries the engine alarm begins sounding and the electric fuel pump starts pumping. When I insert the key and proceed through normal engine starting steps, as soon as the engine is running, the alarm ceases and the pump ceases pumping as well. I thought that the ignition switch might be the problem and replaced it this weekend. I still have the original problem. Has anyone else experienced this problem? How did you fix it?
Electrical Problems
- Thread starter Easton
- Start date
Sounds like you are back feeding 12 volts from somewhere. Probably the alternator. Since you have already had the control switch out, you might check to see which wire is hot when it should not be. That will point you in the right direction for a fix.
I assume you have a diesel engine and if so, you are not complying with proper procedures to shut down your engine. You NEVER shut the ignition key off to turn of your engine like you do in your car. The first thing you do is pull the stop cable which closes off the fuel supply and shuts down the engine. THEN you turn off the key. What you have done is shut off the electrical supply to the engine, but it continued to run under diesel power. You could have blown some diodes or have other problems now. You need to have someone trouble shoot your problem.
Since you mentioned an electric fuel pump noise, perhaps you didn't have a diesel inboard. Not enough info, I guess.
A diesel engine does not require electricity to run, since it fires the fuel through compression, not a spark plug, so it should not really damage the engine by turning off from the key, but it probably just starves the engine for fuel, when your electric fuel pump is switched off. Many diesels were built with mechanical fuel pumps & the starting switch would not even turn them off, as the key really only engages the starter circuit.
I have the simple 5411 diesel engine, which can only be turned off by cutting back the throttle until fuel delivery is stopped.
Turning your engine off from the key would not normally damage your alternator diodes. This usually only occurs if you switch the battery bank switch from 2 to 1 or off while the engine us running. I would replace the keyed starting switch first, as it sounds like it may be shorting in the on position. This would be the easiest & most straight forward item to replace first, to diagnose & repair the problem. Contact Catalina Yachts, as they do keep a remarkable amount of old parts in stock in their warehouse.
I have the simple 5411 diesel engine, which can only be turned off by cutting back the throttle until fuel delivery is stopped.
Turning your engine off from the key would not normally damage your alternator diodes. This usually only occurs if you switch the battery bank switch from 2 to 1 or off while the engine us running. I would replace the keyed starting switch first, as it sounds like it may be shorting in the on position. This would be the easiest & most straight forward item to replace first, to diagnose & repair the problem. Contact Catalina Yachts, as they do keep a remarkable amount of old parts in stock in their warehouse.
Thanks. I had hoped the switch was the culprit and replaced it last week. The problem persists unfortunately.
I would have someone bench test your alternator for bad diodes. I have also heard that there is a fuse located beneath the alternator on Universal diesels, which my have blown from being overloaded. Get yourself a voltage tester, but it may be time for an experienced marine diesel mechanic. Otherwise Niger Calder's book on marine diesel maintenance & boat wiring is the Bible of marine wiring diagnosis & repair. Good luck.