Catalina 30 Electrical Short

[C30 3058]

I have a short in my electrical system that is causing severe battery drain whenever the battery switch is on, even with all devices shut off.

I put a test light in line with the positive terminal and even with all fuses removed from my panel, the light shines brightly. Anyone who has rewired, did you find any obvious places is hould be looking to eleiminate this?

I would rewire, but i have a job, kids etc. and i want to sail this summer!

Thanks!

 

[Stu Jackson]

C30 wiring

I have a short in my electrical system ... Anyone who has rewired, did you find any obvious places i should be looking to eleiminate this?

I would rewire, but i have a job, kids etc. and i want to sail this summer

Wow, how and where do we start here? Did you do any re-wiring recently or in the past? Do you have a wiring diagram for your boat? When did this begin? How long have you had the boat? Has it worked properly and for how many years before?

I love playing electrical detective, but there's no way to even begin to address your question as presented without answers to at least these questions.

When it comes to boat electrical systems, there are no "obvious places" to start based on the little information you've provided. Many people will start with "check the grounds" which is not a bad place to start.

I'd also suggest checking the connections at the back of the -1-2-B switch. Have you opened up your electrical panel and checked back there? Any loose wires "just hangin' around?" What's the condition of the wiring inside your battery box(es)?

There are altogether too many places to recommend that you investigate, and the basic answer with all electrical problems has ALWAYS been "check all the connections."

If it was my boat, I'd start with a wiring diagram, which will force you to trace, and while you're at it, check each and every single wire from the batteries to the switch to the panel to the engine ground. All of them.

 

[C30 3058]

C30 Electrical Short

Okay,

I've owned the boat 9 years, I discovered the short last summer,not sur ehow long it's been a problem, i've never had good battery life. The only new wiring is my autopilot, but I've checked that.

If all the fuses are out, and i still have current flowing, it's clearly something very wrong.

When i asked about "obvious", i was hoping a whole crowd of rewirers would say,"it always chafes through at X location", not so lucky, so i will do it the hard way.

Also, yes i have the original wiring diagram and will first check the post-factory wiring done by previous owner, then systematically through the factory wiring.

Thanks!

 

[C30 3058]

Found it, Bad alternator!

For any that have been following this:

I found the short! I put a test light in line with my battery ground, removed all fuses, and the light still shone brightly. Started in the engine compartment, The alternator was actally warm to the touch, the boat having just been plugged in and on battery charger. I removed the large red wire from my alternator and the light went out. Now i realize that the alternator is always connected even when the key is off.

Hope this helps anyone else with similar problem!

Good sailing.

Paul

 

[Stu Jackson]

I removed the large red wire from my alternator and the light went out. Now i realize that the alternator is always connected even when the key is off.

Paul, thanks for "completing the loop" on this thread -- I was wondering, but now I have a question. What did you do? Many of us have the alternator wired directly to the house bank. Do I understand you to say that you disconnected the alternator output? Somehow I don't understand your "solution" nor does it explain how your system works.

 

[C30 3058]

C 30 Electrical Short

I said I found the problem, not that I fixed it! But of course, knowing the problem is the hard part. I assume i have a bad alternator, so i've pulled it out and intend to replace it, probably with a higher amperage (55A) upgrade. I also will shorten the wiring by eliminating the ammeter in the cockpit as i've read about. The motor is an A4, and i can wire the alternator "output" directly to teh positive lead on teh starter as suggested by Moyer Marine and others. Thsi shortens the charging circuit by a good 20 feet of questionable wiring.

 

[C30 3058]

Closing the loop

I said I found the problem, not that I fixed it! But of course, knowing the problem is the hard part. I assume i have a bad alternator, so i've pulled it out and intend to replace it, probably with a higher amperage (55A) upgrade. I also will shorten the wiring by eliminating the ammeter in the cockpit as i've read about. The motor is an A4, and i can wire the alternator "output" directly to teh positive lead on teh starter as suggested by Moyer Marine and others. Thsi shortens the charging circuit by a good 20 feet of questionable wiring.

Final report: I replaced the alternator with a 55A model from Moyer Marine. The alternator is not wired directly to the house bank, but thru the A-B switch. I wired it directly to the hot starter lead, eliminating the ammeter in teh cockpit. We took our annual summer cruise in August and had plenty of power the entire week with no issues.

Conclusion: If you've got a battery draining short that you can't seem to find, check your alternator.

 

[Stu Jackson]

Thanks for the loop closing

Only suggestion we can make for you now: get the AO off the 1-2-B switch and send it directly to your house bank. Easy to find a switch to charge your reserve bank, just use B when charging after the house bank is pretty full. The reserve bank doesn't need much of a charge anyway, ever.

 

[Bob S]

The switch may be the reason the alternator fried. Lot's of good advice on this and the C34 boards about electrical upgrades.