Mystery electrical system problem - not sure how to proceed.

[AK Angler]

[thataway]

[AK Angler]

That's a great clarification Bob, and I agree completely. But, I would add one caveat...

Regardless of the rated power draw of the attached systems, fuses should always be properly sized to protect the wire - and never, never above that. You can always use a smaller fuse if the system draw is lower. But if the calculated system draw exceeds the proper fuse size for the wire, the carrying capacity of the wire in the circuit (either size or number of wires) should be increased before increasing fuse size.

Big wire with small fuses = good.
Small wire with big fuses = bad.


EDIT:
We're really discussing two issues here.

1) Wire size should be determined based on expected load and wire length, so as not to exceed recommended voltage drop limits.

2) Fuse size should be determined based on either wire size or load - using the smaller of the two to choose the proper fuse.

Typically, wire size will determine the maximum fuse size, and load will determine the minimum fuse size.

[Sunbeam]

Just got back online - another great bunch of replies. I'll address a couple of things (as far as I understand them)

Thataway: I completely agree on the "understand what you have and why." The electrical system is my least understood one, and although I think the new systems I (and the tech) put in are probably good, it has bothered me not to understand them completely. And then too there are the original parts that I have not gone through yet, none of which strike me as overly robust or elegantly simple.

I'm taking this problem as a "kickstart" to my understanding things better and making improvements (myself). Up until now I had a certain pressure from spending a long time working on a lot of projects and not having used the boat yet. Now that I've had the good fortune to spend a month on Powell with a good friend, I'm a bit more relaxed about another (hopefully smaller!) round, including some new-to-me things (electrical). Also, it's nice to have had some experience aboard to help shape my thoughts on how I might use things (of course more time is necessary )

On the Safety Hub: I agree that there may be other as-good or even better ways, but it does have other uses as it stands now than just the one main fuse. There are my two bilge pumps wired into the top "always live" slots, and there was the Wallas in one of those too (before I removed it from the boat; but I may get a Wallas furnace and so it would go there I believe). I'm sure there are other ways to handle the bilge pump loads, (like maybe another bus or something). Not sure I would get it again, but I'll probably keep it for now (I think?) (and of course carry more fuses - I had only the one in there and one spare).

AK Angler: I appreciate your organized scenarios in options for improving things. I don't have most of those things even on the boat yet (radar, a second 12 volt outlet, washdown pump, electric wipers, etc.) but I do want to plan for them. And worst-case scenarios are good to plan for. I'll have to think over how to do it within the options. I believe I want to replace the 10 gauge wire (even if I do put in two wires) just because it is original, probably not marine/tinned, and I'd like to lay eyes on it (as I replace it!)

Astoria Dave: Appreciate your input and thoughts on "future proofing."

Today's update on the mystery problem:

This morning found us with the new 12-volt outlet in place with its 10-amp fuse, and the "main fuse" being a 20-amp blade fuse on the Safety Hub. I had taped over the trim tab switches so I would not use them. We started out by backing into the beach to change props (I wanted to do a WOT test with my original prop), then headed out into Padre Bay to test it. I had just the VHF/Depth/Chartplotter on - nothing else. About two minutes showed the prop to be woefully inadequate (4800 rpm at WOT) (more details in the other thread I started on props), so since we had 25 miles to go (and a bunch of fuel to burn up besides), I headed right back into the beach to change back to my "Powell prop." After shutting down the engine I turned off the depth sounder, then we did the prop switch, and then pushed off, I lowered the engine, started it, looked back to be sure of indicator water stream, and looked forward to see.... no electronics. Darn! Since I was looking back I'm not sure when they went off, other than that they were on after I shut the engine down and tilted it up when I backed into the beach.

So:

- Nothing was even in the (new) cigar lighter outlet
- Just the three "instruments" were on.
- I did tilt the engine back down and start it (not sure if that affects the main fuse, since it still runs without the main fuse).

Granted, we were on only a 20-amp fuse (jury rig), so maybe it's a completely different issue and not really a "clue." I never expected a 20-amp main fuse to be adequate (but then, it IS adequate for a chartplotter, depth sounder, and VHF (no transmitting done). So I'm back to some sort of short or wiring issue (vs. the cigar socket).

Of course, being "pro's" now, we made short work of robbing the 15-amp fuse from the autopilot and putting that in our slot, and away we went, back to Wahweap. No more issues with electricals. Ahhh.

By the time we got our tow rig and trailer back (had to shuttle to storage and back) it was after 4 p.m. Taking one look at how much work it will be to sort things out (i.e. change from living on boat to van), and also needing to burn off some fuel yet, it was an easy decision to putter back to a nearby anchorage for one more night afloat (yay!) Tomorrow morning we'll take out And then we'll be delving preliminarily into the electrical while still here (mostly looking over wiring for shorts/chafing/other issues), plus cleaning/sprucing/winterizing. Later will come upgrading some of the electrical system -- before the next boat trip (plus laying in a stock of fuses!)

Sunbeam

[AK Angler]

While it's certainly disappointing that the new 12V outlet didn't solve the problem, at least you can now rule it out with a pretty high level of confidence. So, of course, the next step is it to check out the main house feed.

Hopefully you won't run out of 'spare' fuses before you get this ironed out.

[forrest]

Sunbeam,
Is it possible that you have a parallel connection downstream from your "safety hub" that allows part of the current for your trim relays to pass through the fuse that you are having trouble with? If you have a parallel circuit, the current will be divided over both branches according to their resistance. If the circuit that normally carries the current for your trim relays is partially corroded, the current to run them may be diverted through other parallel paths. Backfeeds can be tough to find and can be a source of intermittent problems. If you have two bilge pumps on one common manual switch, that would be a backfeed. Look for a tie between the two batteries on the load side of your safety hub. You could be getting a backfeed through the hub in the reverse direction while starting the motor if one battery is stronger than the other.

[colbysmith]

My best guess says a short somewhere in that main wire going from the fuse that keeps blowing. Perhaps the sheathing chafed off at a screw somewhere, etc.

[AstoriaDave]

Sunbeam,

If I understand Forrest correctly, he is suggesting a bad ground on a high current load may be the culprit. A look see, with the aid of a squirt of Corrosion Block and a loosening and retightening of suspect ground terminals may ferret this out without any highfalutin' meter work or other brain cramps. Any ground connections which show lots of corrosion should be replaced ... here is hoping the wiring is marine grade.

[anchorout]

Sunbeam:
I know this is all confusing, but it is very hard to troubleshoot over the net, without being onsite to physically see how things are wired. These boats were probably originally wired the same (I have schematics in my owner's manual). But most have been modified to carry more current to feed more goodies. The boat I recently bought had a separate fuse panel under the sink. I spent 3 days straightening out the wiring.

Personally, once I understood where and how the safety panel was used, I have ordered one for my boat. It beats having multiple runs with inline fuses, all piled onto a battery terminal.

On my boat, the engine circuits, that is the tilt/trim, dash engine instruments, starter solenoid, etc are insulated from all other circuits on the boat. In other words, nothing I do with the engine should cause current to run down the wire to the main fuse panel. In your case, through the 30amp fuse. So, on your last episode, either something is wired so as to cross talk with the engine circuits, doubtful, or we are still chasing the elusive short circuit.

Whatever the fix turns out to be, I'd give you a free ride to fish the rigs in the Gulf to know what you finally find. Again, good luck.

[Sunbeam]

[Sunbeam]

Hi all,

Thanks again for the great input! Just so you know, I've received a private message from another 22 owner (who doesn't have an electrical problem) who said he's gotten a lot out of reading the thread, and will be casting a critical eye on parts of his electrical system as a result. I was happy to hear that this "gold mine" of information isn't helping only me.

Today we pulled out of Lake Powell. Feels weird to be back on land: Wal-Mart (food), traffic....the full catastrophe

But back to the "exciting" news (ahem): We spent last night anchored out across from the ramp, and had Episode 4 in the saga, and then this morning Episodes 5 and 6. A veritable bonanza of clues Although we have not found the source of the problem yet . Tomorrow morning will be the massive boat washing/un-loading, and then we dive into the electrical.

Below I'm going to summarize all 6 "episodes," just so it's all laid out in one place. I also remembered a couple more details from the first time, which may help. But before that, I'll just say that none of the wiring on the boat looks at all corroded or "old." Now that said, it's nothing special in the "tidy and elegant" department (yet!), and there is obviously a problem (which I am determined to find), but basically overall it all looks fresh and clean.

So, back to the summary. I'll write a bit of "chatty stuff" about each time, and then summarize the facts so those who only want to read that part can skip the drivel

Episode #1
After running around Lake Powell for three weeks in all types of conditions with no problems, one day about 10 days ago found us in a small, glassy pool area way back in a canyon. At first I drifted with the engine running in neutral, but soon I found that the boat would pretty much stay where she was anyway, so I shut the engine down and we decided to eat lunch while enjoying the silence and scenery. I left the VHF and GPS on, and my laptop may have been plugged in with the small inverter to the cigar lighter, but I can't remember for sure about that. Nothing else was on. After about five minutes we had begun to drift toward one wall, so I started the engine, reversed a hair, and then shut it off. The trim tab auto retractor ran (I now remember that it ran the full 15 seconds, and did not "cut off" early), and then after a moment when I looked back forward I noticed "hey, the instruments are all dark." I checked and the engine still started fine, and the engine-specific gauges worked. We looked and found the main (30 amp) fuse blown, and put in my spare one. We also decided to disable the trim tab auto retractor just in case, and because I found I didn't like it anyway. All then functioned great for 8 days of running around fast and slow, living aboard, and etc.

*********

Summary of Episode #1

After three weeks of cruising with no problem
Drifting in glass calm water
VHF on
GPS on
Laptop maybe plugged into cigar lighter
Started engine, reversed slightly, shut engine off
Trim tab auto retractors cycled fully
Shortly thereafter I noticed GPS and VHF were not on
Main 30 amp fuse was blown.
We put in spare 30-amp fuse
**********

Eight days later, on another glass calm day, we motored at hull speed for a couple of hours out of another deep canyon. Then we planed to a "potti island" (like a floating dock) and tied up. I shut down the engine but left the VHF, depth sounder, and GPS on. Buddy's phone/tablet were charging in the cigar lighter through a USB adapter plug.

We spent around 45 minutes on the dock, emptying the porta potti and then chatting with the maintenance fellow and his ride-along dogs there, whom we'd run into previously up-lake. Then I went aboard and got online to check weather and C-Brats (but computer was completely unconnected to boat and just running on its internal battery). A few minutes later my buddy said "Uh-oh.... the instruments are all dark." Nooo! Yep, the spare 30-amp main fuse was blown. That's when I started this thread. Then we traced each electrical item on the boat to its fuse and found the cigar lighter was not fused (everything else was). We replaced the cigar lighter socket with a new Blue Sea one I had aboard, put it on an unused slot on the fuse block with a 10-amp fuse (for now), and re-wired the main fuse to utilize a 20-amp blade fuse (knowing we would go easy on the draws).

************
Summary of Episode #2

Eight days after first one
Tied to a dock in glass calm water
Engine off (no more trim tab retractor as we had disabled it)
VHF on
GPS on
Depth sounder on
Phone/tablet plugged into cigar lighter
After an hour or so buddy noticed GPS/VHF/Depth sounder were not on
Main 30 amp fuse was blown.
Put in 20 amp fuse (spare)

**************

From the potti island we planed about 7 miles to our next anchorage. We didn't use the trim tabs although I did charge my laptop for a half hour or so. All went fine. It was a quiet night at anchor. The next morning I started the engine and backed into the beach so we could change props (testing a few of them on this trip). Shut off and tilted engine, changed prop. Then went out exploring and shortly thereafter did a WOT run. It was a glassy, windless day - perfect for a test. I used the trim tabs once - just set them for planing and then did my WOT run. WOT was not satisfactory, so I ran back to the beach, backed in, shut off engine and tilted it up, then shut off the depth sounder. Then we changed the prop. I had left the VHF/GPS on during this.

After the previous prop was back on (five minutes), I went to the helm and my buddy shoved us off. When we got to deeper water I trimmed the engine down, started it, and looked back to see the "pee stream" start as is my habit. Next I went to turn the depth sounder back on and saw.... no instruments. By now we were getting pretty quick at this, so I took a 15 amp fuse from the auto pilot slot on the fuse block and we put that in as the "main" fuse. By now we were not using anything that drew much -- no more tab use, retractors remained unhooked (and will stay that way as I don't favor them). Basically just running with instruments and engine.

**************
Summary of Episode #3
One day after second one
Shoved off beach in glass calm water
VHF had been left on
GPS had been left on
Tilted engine down and started it, watched for pee stream
Turned forward and reached to turn on depth sounder and... found all instruments were dark.
20-amp fuse was blown
Put in 15 amp fuse from autopilot (stock was running low!)
(Nothing was plugged in to new cigar lighter.)

***************
Then we ran around 30 miles back to the launch ramp area. It was not very windy, but (as anyone who has boated on this particular stretch probably remembers) it is a sort of "Maytag Straits." The walls are sheer rock and it's narrow, and it gets very rocky/rolly/bouncy due to reverberating boat wakes. We stayed up at about 12 knots, and definitely did our share of rocking and rolling (got waked pretty good two or three times). But we pressed on and all went fine. We stopped at the Wahweap store for (much appreciated!) food, and I went and got the tow vehicle from storage. In the evening (yesterday) we puttered across a quiet bay and anchored on yet another glass calm night. We had three things on: The GPS, the LED anchor light, and the trim tab indicator LED lights (they stay on by manufacturer design). After a couple of hours and another nice moonrise, we noticed "Gee, it seems kind of dark in here." Yep, the instruments and anchor light had gone dark. Three guesses why....

We robbed a 10-amp fuse from the cockpit spotlight slot and put that in as the main fuse, then kept the GPS and anchor light on. I couldn't see how it could be the trim tab relay (it is attached to the positive bus along with the helm feed wire), but just to be sure, I pulled its inline fuse. So no powered relay, and no LED indicator lights at helm. Then I just had to start sleuthing again. I remembered a mechanic friend telling me that sometimes you can notice things at night with a good flashlight that you cannot see during the day so I figured, why not look around now.

I traced the main helm feed wire from the fuse block behind the helm back to the positive bus. I could see it most of the way and it looked fine. There were a couple of places where it was in the middle of the wiring bundle, but I could not see anything there that could be getting in to disturb it. No cable ties, screws, etc. (Of course we'll be looking at it further, but this was just preliminary because I had to do something.)

I then traced the (not long) wire that leads from the positive bus to the main battery switch - that looked fine (and was new put in by me recently). I wiggled all the (new) wires around the main battery switch. I did find that that wire from the positive bus was slightly loose. I wiggled and pulled on it like mad while keeping my eye on the anchor light but nothing even flickered. Also I think if that did cause a problem it would not blow the main fuse anyway. I'll be tightening it after that whole switch/wires are looked over tomorrow. I then went behind the helm and looked over the fuse block, wiggled everything, looked for any negative wires that might be causing a short... didn't find anything. Went to bed and slept poorly; mentally started writing this post around 4 a.m. But the light/GPS stayed on all night with no further problem.

*****************
Summary of Episode #4
One day after third one
Anchored in calm seas.
GPS was on
LED anchor light was on
Trim tab indicator LED's were on
(Nothing was plugged in to new cigar lighter.)
After a few hours we noticed it had gotten "dark"
15-amp main fuse was blown
Put in 10 amp fuse
Removed fuse from trim tab relay, disabling relay and LED indicator lights
Left GPS and anchor light on
They stayed on all night.

****************

This morning we needed to "get rid of" some fuel, so we alternately planed and puttered around Wahweap Bay. We were running with just the GPS/VHF/Depth sounder. It was a sunny, glassy morning (I know, it sounds like it is glassy all the time, but we spent literally days - a few times - holed up for blows earlier on this trip). After a few hours we went over toward the beach and shut down the engine and drifted while we measured out and added Stabil to the fuel tanks. After we finished that I started the engine and noticed .... all the instruments were dark (groan). I didn't notice if the engine starting affected them or not, but just noticed shortly after the engine was running that they were off. We dug out a 10-amp fuse (from the cabin lights slot...) and set out to let the Stabil "mix in" (we were in sight of the ramp by now). I guess this means the trim tabs are off the list as they were completely disabled (their fuse was pulled last night and left out).

****************
Summary of Episode #5
One day after fourth one
Drifting in calm seas.
GPS was on
VHF was on
Depth sounder was on
Trim tab relay and LED indicators were completely disabled (fuse pulled)
(Nothing was plugged in to new cigar lighter.)
After re-starting the engine I noticed the instruments were dark.
10-amp main fuse was blown
Put in another 10 amp fuse.

******************
Now we shut down the main engine (still nice calm seas) and went to start the kicker to let it run to get the stabilized fuel into it, and then let it run out of fuel (will drain carbs later). I think we breathed on the handle (ha, enrichment circuit) because it would not start right away. I went to the helm to re-start the main engine but before I even turned the key I noticed.... yep, the instruments were off. Well this is getting old! We put in another 10 amp fuse and then buddy suggested disconnecting the ACR. Okay, sure, let's see if it blows again, in which case we can eliminate that.

**************
Summary of Episode #6
Same day as fifth one (today)
Drifting in calm seas.
GPS was on
VHF was on
Depth sounder was on
Trim tab relay and LED indicators were completely disabled (fuse pulled)
(Nothing was plugged in to new cigar lighter.)
Engine was off
Instruments went "dark" while engine off
10-amp main fuse was blown
Put in another 10 amp fuse.
Disconnected the ACR (automatic charging relay).

****************
After this we got the Honda started (operator error the first time), ran around on it for 20 minutes or so to get the stabilized fuel into it, then pulled the fuel line (and ran, and ran.... until it finally ran out of fuel). Then we re-started the main and went around a bit more, almost hoping for Episode #7 so we could eliminate the ACR, but finally we just had to retrieve - the ramp was starting to get busier and we wanted to get onto the trailer (and go get more food!). But... there was no episode #7 (yet).

Since we're going to be spending a couple of days getting the boat squared away, we decided to leave the GPS and VHF on for now (on the trailer), just to see if they would "blow" again. We left the ACR disconnected. I just looked.... instruments are still on....

After we get the boat cleaned/emptied and organized, then we'll start poring over the wiring (including that pesky helm feed) and electricals.

Sunbeam

PS: I can't wait to find out why this never happens when we're bouncing along in a seaway, but rather only when we're on a glass smooth sea and or not even moving on a glass smooth sea. Puzzling!

[AK Angler]

Definitely puzzling... I'm going to have to ponder these last few failures for a bit.

[AK Angler]

Sunbeam, I've been looking at the electrical pictures you have in your album, and I'm thoroughly confused. Lots of questions here...

With the possible exception of the ground wire, the ACR should be connected directly to the batteries - and only the batteries. Is your ACR connected to the SafetyHub?

What else is connected to the positive lug on the SafetyHub? Does that wire go to a battery? Does it go the the switch in the next picture?



Also, I can't tell from your pictures, which switch do you have?

Are there only two red wires connected to that switch? Where do they go?



Finally, just to make sure I'm actually seeing what I think I'm seeing in your pictures...

How many batteries are you running?
How many engines are connected to the boat electrical system?
How many battery switches do you have?

[Sunbeam]

[AK Angler]

Thanks for taking the time to write all that up. I'm pretty sure I could follow everything. I'm gonna go make myself a couple of sketches, and stare at 'em for a bit...