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Help: Strange Electrical Issue

Posted: May 2nd, '12, 23:27
by JohnV8r
Hey Guys,

I've run into a strange electrical issue on Shambala. My cabin lights, stereo, nav lights, and instrumentation are not coming on UNLESS MY SHORE POWER IS PLUGGED IN. Those systems are on separate circuits. Additionally, all of those circuits will turn on & off with the breaker switches.. Other systems, like the blowers and my electronics that are connected to the same side as the non-working circuits come on with just battery power.

I just replaced the batteries on the side that has the working & non-working circuits, so I'm confident the issue is not bad batteries. Can anyone point me in a logical direction to find the issue.

Thanks in advance.

JohnV8r

Posted: May 3rd, '12, 07:36
by bob lico
The panel has a jumper between buss bars for positive (breaker bar) and the negative has the same arrangement .the jumper is bad between the bar that has the working devices and the buss bar that has the devices that are not working

Posted: May 3rd, '12, 07:37
by RAWicklund
Electrical problems are always hard to diagnose over the phone / internet etc.

But my best guess would be conection issuses with the battery you replaced.

Since circuit works on shore power, I'm guessing it is getting power from Batt charger/inverter and not the battery. So maybe charger wire got left off on reinstall?? A place to start maybe.

Ray

Posted: May 3rd, '12, 07:59
by Charlie J
think bob hit the nail on the head with the jumper bar

Posted: May 3rd, '12, 10:16
by JohnV8r
Thanks guys. I have the old house style DC panel if that makes any difference in the analysis. I'm going to pull the Panel this morning and test the jumpers with a multimeter. I'll also recheck the battery connections. I cleaned them up pretty good prior to install. I also checked the batteries yesterday to make sure they were at a full 12 volts.

It never fails that a problem pops up right before a survey.

Posted: May 3rd, '12, 10:19
by JohnV8r
I have two Group 31 batteries on each side.

Posted: May 3rd, '12, 11:22
by Mikey
Follow Uncle Vic'd advise on all things electrical. Annually squirt all connections with Corrosion X. If you haven't done so recently give everything a shot and then wait 24 hours. Magic happens!

Posted: May 3rd, '12, 12:36
by JohnV8r
I got out the multimeter and Here's what I found:

Image

With the shore power connected, I have voltage on both sides of the positive connections to the DC breaker panel - the two red wires coming down each side of the panel.

With the shore power disconnected, I have power to the left positive side of the breaker panel, but NO POWER to the right side positive lead. In both instances, I checked for voltage by touching the negative/ground of the multimeter to the negative bus bar and the positive lead of the mm to each positive side of the breaker panel.

I checked the battery connections, and they appear to be good coming immediately off the batteries. I tested for voltage at the first connections on the bulkhead and had power.

Therefore, it would seem to me that the issue is somewhere between the batteries and the DC breaker panel. Is there some type of fuse between the batteries and the panel?

Posted: May 3rd, '12, 13:14
by In Memory Walter K
Could you have a bad circuit breaker? If you connect a heavy gauge wire between your left and right red wires does your problem go away?

Posted: May 3rd, '12, 13:32
by In Memory of Vicroy
Ground. You have a bad 12 v. ground and the whole system is grounding thru your shore power, which I think is what Charlie, et al are talking about with the bus bar?

UV

Posted: May 3rd, '12, 14:00
by Charlie J
iam confusded your shore power should be 120 v ac your dc panel should be separate, your only common conn should be your nuetral tie and pos side of batt charger

Posted: May 3rd, '12, 14:24
by Charlie J
ok re read your first post, look for the common ground conn could be bad or corroded

Posted: May 3rd, '12, 15:08
by Mikey
If the last word in Charlie's post (corroded) is correct (and I'm betting on it) refer to my first post. Squirt the crap out of it!

Posted: May 3rd, '12, 15:23
by Bruce
If your still using that old breaker panel my guess is you still have the cylindrical fuses on the bulkhead that snap in place?

And as been stated before you have power cause of the charger. Doubt its a ground as the charger doesn't switch or combine the grounds and it should have no effect on a bad ground.

Posted: May 3rd, '12, 16:22
by JohnV8r
Case closed. In what I can only describe as my second most embarrassing moment in 9 years of Bertram 31 ownership, the culprit was a negative battery cable that slipped all the way under my engine. It is the second ground wire that goes on my paralleled Group 31 AGMs, so it wasn't like there was an empty negative post. However, I feel like a big douche bag!!!

And for the record, the most embarrassing moment was when I moved my shifters forward to polish them and then had to call Wayne Fultz for help figuring out why my boat wouldn't start. That was a similarly beautiful moment.

Posted: May 3rd, '12, 16:27
by Charlie J
ive done the shifters to

Posted: May 4th, '12, 14:41
by Mikey
John,
I revert to my two previous posts. A squirt between the ears has worked very well for me in the past.