Electrical Problme

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Jul 19, 2007
3
- - summerwind
Folks, After a nice afternoon sail on Buzzards Bay I came in and discovered a strange electrical problem that has me stumped. All my devices powered by DC voltage are not working. That includes instruments, potable water pump, sump pump, macerator pump, lights, stereo, etc. I get 12+volts to the DC power switch, also get 12+volts to the fuse and also to the switch for each device when in the "on position". I also get 12+volts to the pumps, etc but they are not operating. Anyone have a clue? Thanks, Jack McLaughlin Summerwind 1986 Catalina 27 6264
 

Dan H

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Oct 9, 2005
143
Catalina C25 SW Michigan
The one common thing is.........

no ground. Check the -12V side of all the circuits. When you get one fixed, all the rest will work.
 
R

Ralph, SV Naner Moon

You need to be well grounded.

From what you say you have battery to all of your equipment, but is it able to get to ground. A better word for ground mite be battery return. The power returns to the battery over the ground system. A open or high resistant connection back to the negitive post of the battery will cause this problem.
 
Nov 12, 2006
256
Catalina 36 Bainbridge Island
Eletrical Problem

Where are you reading from? Are you using the negative terminal of the battery? If so, find a common ground connection for the circuits you are checking to see if you still can measure 12v. I agree with Dan and Ralph.
 
Feb 5, 2007
73
Catalina 27 Standard Rig Point Cadet Marina, Biloxi, MS
Inboard?

The other post hit nailed it. And, if you have an inboard don't miss checking the ground point on the engine.
 
Jul 19, 2007
3
- - summerwind
How to find an electrical short

Sounds like I have a short somewhere. What is the best way to find the short?
 
Jun 3, 2004
145
Catalina 27 Stockton CA
No short

It's not a short. A short circuit happens when the hot and ground leads (+ and -) somehow connect with each other outside the regular circuit, before the juice gets all the way down the circuit to the appliance. (By "appliance", I mean anything that is wired in to use your 12 volts - running lights, stereo, pumps, etc.) When a short happens, you either blow a fuse (or trip a breaker), or you may have a fire. Sounds like you have an "open circuit", the opposite situtation, where one of the wires breaks or become electrically disconnected from the circuit so no (or not enough) juice can flow out to the appliance from the battery on the hot lead and back to the battery down the ground lead . As the others have mentioned, it's likely a bad ground. Since NOTHING works, its likely in the circuit coming from the battery to the fuse panel that distributes out the electricity to all the appliances. To isolate that, use the impedance testing function on your multimeter, and connect one end to the battery ground terminal, and one at a time to the other end of the ground wire in each circuit. The meter should read zero, or close thereto if the circuit is good. When you've found the bad one, you'll get a high (or infinite) reading on the meter. One other thing to be aware of is that you might have a bad ground that allows current to pass, but just not enough current to run the appliance if it uses a lot of current. The instruments usually use little current, the bilge pump, macerator etc. use a lot. If that is the case, then your meter may show you have a good circuit, because the meter only draws a very small amount of current, but not enough can pass to run the appliance. But in your situation, since NOTHING works, it would have to be a VERY bad (but still existant) ground to prevent ANYTHING from working. Good luck!
 
Jul 19, 2007
3
- - summerwind
electrical problem

I solved the problem. It was a corroded terminal on the negative terminal of the battery. Thanks for the responses that pointed me in the right direction and saved me a bunch of money by not hiring the marina to solve the problem.
 
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