Electrical Mystery

karista · January 07, 2014, 07:12:01 AM

About one time each month I check my navigation lights. I do this by turning on the switch for each light (Running/Steaming/Deck/Anchor), and watch the Link for amperage draw. The average Amperage draw for the Steaming and Anchor is about 0.7 Amps, the Running Lights have always been around 1.2 Amps. This time however the Steaming and Anchor light each showed the normal 0.7 Amps, the Running Lights however showed a shocking 32 Amps, yet the 20 Amp Circuit breaker did not pop.
I tried this several times and each time the running lights registered 32 Amps.
The Link works correctly as I tested it by turning on various other devices. I don't understand how, if indeed there was such a Amperage draw why the Circuit Braker did not pop and also what could cause such a high Amperage reading.

2ndwish · January 07, 2014, 08:23:38 AM

At 32A you are dumping some 360W somewhere, so something is getting pretty hot. Are the lights working? Assuming the current read is correct, you would see other lights visibly dim when the running lights are switched on. If the read is correct, you have both a bad breaker and a short somewhere. 360 W is enough power to get something very hot in a confined space so be very careful with this!

Roc · January 07, 2014, 08:57:14 AM

I seem to remember reading somewhere on this site, someone's running lights wire was touching the bow rail, causing the metal to be electrified. You might want to CAREFULLY see if the rail is charged.

Ron Hill · January 07, 2014, 02:29:58 PM

Bernd : I agree with Roc.

Be careful of the bow pulpit as it could be that the wires have worn off the insulation (rough hole edges) where they enter or come out of the stainless tubing.

A thought

karista · January 09, 2014, 01:10:06 PM

Quote from: 2ndwish on January 07, 2014, 08:23:38 AM
At 32A you are dumping some 360W somewhere, so something is getting pretty hot. Are the lights working? Assuming the current read is correct, you would see other lights visibly dim when the running lights are switched on. If the read is correct, you have both a bad breaker and a short somewhere. 360 W is enough power to get something very hot in a confined space so be very careful with this!

I checked the situation today, and for sure the cabin lights dim, also I bypassed the existing breaker with a 20 AMP fuse, turned on the running light switch and the fuse immediatly burned out. So, you are correct, I have a short somewhere and a bad 20 AMP breaker.
I am not sure how Catalina routed the wires, but this will be a weekend job to find out!

DaveM · January 09, 2014, 01:48:50 PM

Friend had a Catalina and after being shocked several times found that the factory ran the Nav light wires under the backing plates for the stantions and push pit. Result was hot stantions and push pit after a while. Not the only case I have heard of this around here on a Catalina.

Might be worth checking with volt meter.

Goodwinds
DaveM

Ron Hill · January 09, 2014, 02:37:47 PM

Benrd : The running light wires going to the bow run along the port side and start at the main electrical panel, up behind the teak trim above the top shelf, behind and inside the port teak trim in the Vberth, thru the port side anchor well and inside the bow pulpit to the nav light.
Stern light wires go along the port side, thru the head, the port locker, engine instrument panel and then into the stern pulpit (pushpit).

I'd look/feel (with the power OFF!!) thru the Beckon port in the bow of the anchor well at where the wires enter the bow pulpit - you might be able to fell the fray in the wire. I'd also look at the wires where they come back out of the pulpit to the bow light fixture.
Then you also need to check the wire to the stern light the same way - where they enter the stern tubing and where they come out to the light fixture.

Good Luck and keep us posted.

2ndwish · January 09, 2014, 06:56:58 PM

Using Ron's information, it is likely that there are two separate wires on the output of the breaker- one for the bow and one for the stern. If you disconnect the wires first, you can use a voltmeter to measure the resistance between each of these wires and ground. Make sure you are looking at the wires on "light" side of the breaker, not the battery side. One wire will read ~30x lower resistance than the other. That's the one with the short. You can verify it by taking out the bulb and the resistance will not change. Won't tell you where the short is, but at least it narrows it down. You sound pretty handy so you've probably thought of this already.

Unnerving about the breaker. I seem to recall a comment somewhere on this board that blasted the use of breaker/switches for this reason.

Really surprised that someone can get a shock from a 12V battery- maybe with wet bare skin on the back of your arm? Like a 9V battery on your tongue. On the other hand you can get a pretty good shock if the pulpit is grounded to the house ground and there is a ground fault from the shore power- different problem though

karista · January 12, 2014, 11:26:08 AM

Quote from: Ron Hill on January 09, 2014, 02:37:47 PM
Benrd : The running light wires going to the bow run along the port side and start at the main electrical panel, up behind the teak trim above the top shelf, behind and inside the port teak trim in the Vberth, thru the port side anchor well and inside the bow pulpit to the nav light.
Stern light wires go along the port side, thru the head, the port locker, engine instrument panel and then into the stern pulpit (pushpit).

I'd look/feel (with the power OFF!!) thru the Beckon port in the bow of the anchor well at where the wires enter the bow pulpit - you might be able to fell the fray in the wire. I'd also look at the wires where they come back out of the pulpit to the bow light fixture.
Then you also need to check the wire to the stern light the same way - where they enter the stern tubing and where they come out to the light fixture.

Good Luck and keep us posted.

This is turning out to be one horrible job! First tried to remove the forward and stern running lights to diconnect the wires to isolate the short to either the wiring or the light assembly. Could not get the the lights off, the screws were frozen in, finally broke the lenses and disconnected the wires. Turned on the switch, Link still read 35 AMPS, so now I have 2 broken lights and no further in finding the short. Per Ron's advice I removed the forward teak trim section and that was a job in itself. Removed the Beckson cover in the anchor locker, and found the wires there to be ok. I then cut the wires in the V-Berth, applied 12 VDC to the wires going to the light (pulpit), it showed 12VD, so that isolated that section as being ok.
So, now it must be in the stern wiring or where the forward and stern wiring are joined. The problem I am having, there is virtually no way to get to joint wire connection as Catalina wrapped all navigation light wiring together tightly into one harness, and it is in the lower section of the electrical panel compartment.
So my thought is to find the stern light wire before it enters the electrical panel compartment, cut it, apply power and check the amperage draw, if ok splice in a new section, join it with the forward wire and connect it back to the switch.
I don't know where the stern light wires actually enter the electrical panel compartment. Ron, you provided detailed instruction of the wiring in general, do you know where exactly the stern light wires enter the electrical panel and how they are routed just prior to the panel?
Catalina used small gauge gray covered no marine grade duplex wiring exiting the stern pulpit, I can't find this size duplex wiring anywhere close to the panel.

Stu Jackson · January 12, 2014, 01:10:22 PM

Bernd, on my boat, the wiring from the aft section of the boat comes in through the port locker into the area above and inside the mirror doors for the medical cabinet. They then continue through the black door fronted cabinet above the nav station and then into the electrical panel.

Rather than cutting the wire, you might want to consider finding it and removing it from the breaker/fuse instead.

Good luck.

BTW, the wiring connections AT the lights are firmly suspect. See this from when we repaired our steaming light. The tiny connectors could well be your issue if that's what you've found when you removed your lenses.

http://c34.org/bbs/index.php/topic,3533.msg23968.html#msg23968

PS - when you replace the light fixtures, use Lanocote on the screws where they go into the fixture so you'll be able to disassemble them again in the future.

Ron Hill · January 12, 2014, 03:05:56 PM

Bernd : I believe the running light wires come out of the main electrical panel thru the teak enclosure with the holding tank vent hose (next to the aft slider).
I "suspect" the running lights wire is slit to the aft and bow lights just above the port side shelf just aft of where that cabin light is wired in. There are a bundle of wires in that "run".

Hope this helps.

karista · January 15, 2014, 12:53:24 PM

Thanks for the reply and info! I am pretty sure that the short is where Catalina spliced the stern and bow wires together with the lead wire to the switch. This area is extremely difficult to to access, it would also mean opening up the tightly wound harness which includes many more wires. I have instead installed new marine grade wiring for the bow and stern running lights and used a dual spade terminal at the switch to connect each wire, this will make it easy in the future to check each light run indivually.