Circuit Breaker Popping! Thoughts?

[lazypp]

I just replaced the starboard dock light (headlights) on my 2004 Ebbtide 210 Campione (Volvo Penta 5.0 Gxi/SX 270 hp). The new bulb failed to work, so I assumed it was not receiving power. Went out last night only to find that now my port one isn't working either, due to a dock light circuit breaker pop, and re pop. I am reasonably confident the port light did work initially after changing the startbord light.
I did get into the instrument panel briefly trying to clear a speedometer line, so I suppose I could have bumped some wiring.
I'm guessing I have two problems. The first being a power supply problem to the starbord light, and the second being a new short somewhere in the dock light wiring.
I don't have a clue how to chase down a short, and I think that is where I should start.
Any suggestions would be greatly appreciated. I do have a test light and voltmeter.
Thanks a ton!

 

[dewey0726]

Re: Circuit Breaker Popping! Thoughts?

Finding a short really isn't that hard. There are several ways to do it. The easiest may be to isolate the short. Remove part of the breaker still pops. When i no longer pops you have removed the short. You can use an ohm meter and removed the bulbs. With the bulbs out you should see infinite resistance. If not go to where the wiring splits for the 2 lights and isolate which side has the short or see if it is towards the switch. It can be confusing at first and it may help to draw a wiring diagram to help you and write notes on what you have checked. I've troubleshot electronics for over 22 years now. If i can keep a job doing it anyone can.

Tim

 

[kenworth747]

Re: Circuit Breaker Popping! Thoughts?

Tims idea is good but first make sure that both lights are still good by seeing if the filiments are still good or by direct contact useing the batt or a battery charger will work, if both are working then those are good,
then before putting the bulbs in turn lights on to see if breaker breaks, If so you have a short in the wireing.
If the breaker doesnt break then put the bulb in one socket and try again if this one breaks the breaker then pull it and try the other socket after pulling the other one, basiclly if there is a short in the wiring it should break the breaker with both bulbs out.
but if it didnt then what ever bulb you put in breaks that breaker it could be all you need is a new socket on that side.
Hope this helps some , and good luck.

Steve

 

[kenworth747]

Re: Circuit Breaker Popping! Thoughts?

Sorry i forgot
theres a possibility that your switch could gone bad also you can take the wires off the switch and use a battery charger to test the lights and the lines
when you go to hook up the possitive lead if there is a short youll get a larger spark when tring to connect it thats when you stop and look for shorts.
reason i say use battery charger is because you can damage the battery if you do this , not only that but the meter on the batt can tell you if your shorting out if it jumps all the way over if it doesnt then that line is good.

Steve

 

[lazypp]

Re: Circuit Breaker Popping! Thoughts?

Thanks Tim and Steve. I greatly appreciate your suggestions. I'll give it a try and see what I find.
Dan