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Need help troubleshooting marine electrical issues

Old 06-08-2019, 01:53 PM
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Default Need help troubleshooting marine electrical issues

Vessel is a 1999 Chris Craft 320.
Just had one engine replaced, and some mechanical work on the other. Motors are working fine, however, I'm now getting various strange problems with electric features not working:

Bilge pump wouldn't operate. Replaced it, was working a month ago, then stopped working.

Removed new pump, tested manually with 12v source, pump works. Metered the leads supplying power to the pump, get 0.5v DC. I can see there is a breaker installed in the engine bay that says "Bilge Breakers", there are three switches, Main, Front and Aft (Boat has 2 bilge pumps). Rear breaker is not popped and can be popped manually and reset. The only other control I can find for the bilge pump is a switch on the dash "FWD, Off, AFT" this is for manual control of the bilge pump.

Also in the bilge pump circuit there is a "Sure Bail" float switch.

The only other electrical fuses or breakers are the switch panel in the cabin (no control for bilge pump there) and a small 10fuse panel behind the VHF radio in the console. 1/2 of these are not labeled, the rest are for things like "TV Antenna" and Radio.

Could there be another panel or control someplace in the boat where power to the bilge pumps could be interrupted or turned off?

Do marine wiring connections need to be "refreshed" or de-corroded from time to time? Could the breaker (looks to be original) be failing or corroded?
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Old 06-08-2019, 02:02 PM
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I had exactly the same problem as you. Mine turned out to be a bad breaker. Replaced it and no issues since.

Multimeter used and took 5 minutes to diagnose.


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Old 06-08-2019, 02:07 PM
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Measure voltage in front of breaker and behind the breaker. And then go from there
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Old 06-08-2019, 02:17 PM
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Try measuring the +12v side of the pump using a bit of wire to connect the -ve lead of the meter direct to the battery -ve post. That will tell you whether there is a corroded -ve feed to the pmp or a bad+ve feed.
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Old 06-08-2019, 02:58 PM
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Originally Posted by Aliboy View Post
Try measuring the +12v side of the pump using a bit of wire to connect the -ve lead of the meter direct to the battery -ve post. That will tell you whether there is a corroded -ve feed to the pmp or a bad+ve feed.
Could you explain this a little more for this dummy?

Are you saying connect the negative meter probe to the negative post on the battery, then connect the + meter lead to the + power wire to the pump?
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Old 06-08-2019, 03:24 PM
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Originally Posted by bluelair View Post
Could you explain this a little more for this dummy?

Are you saying connect the negative meter probe to the negative post on the battery, then connect the + meter lead to the + power wire to the pump?
Don't feel bad, I've been doing this stuff for 40 years and I have no clue what that means. Most likely a corroded connection.
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Old 06-08-2019, 07:59 PM
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Since your bilge pump works outside the boat, you have current issues in that set of wires. I always go for the ground first. But even before that, do you have any other electrical issues? Do any of your bilge pumps work?

If yes, then start looking at your main grounds. Each battery. Then both sides of the battery switches. Then at the motors.

If no other electrical issues, go to the leads where you unplugged the bilge pump. Have a powered meter that shows you + and -, as well as beeps for continuity, not just a light bulb. Test continuity on your ground to some other ground. If that doesn’t beeeeeep, you have a ground issue. Also test the hot leads (one should be constant (auto bilge) and one should be switched. If you have a good ground you should see that you have 12v+ constant and then 12v+ when you hit the manual switch. If you don’t have 12v+ constant and you have good ground, then there’s one problem. If you have 12v+ switched and good ground, then back up to the switch. Test 12v+ in front of the switch. Should be hot. If yes, Test 12v+ behind the switch (going to your bilge pump). If 12v+ is going into the switch, but not coming out (make sure to turn it on), viola. If you don’t have 12v+ going into the switch, backtrack that further.

But, my money is on a crappy ground somewhere. Feel and flex your grounds. They shouldn’t be green, brittle, or otherwise corroded.
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Old 06-09-2019, 04:53 AM
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Originally Posted by Aliboy View Post
Try measuring the +12v side of the pump using a bit of wire to connect the -ve lead of the meter direct to the battery -ve post. That will tell you whether there is a corroded -ve feed to the pmp or a bad+ve feed.
Originally Posted by sjef View Post
Don't feel bad, I've been doing this stuff for 40 years and I have no clue what that means. Most likely a corroded connection.


What Aliboy so eloquently described is testing of power supply and ground.
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Old 06-09-2019, 07:08 AM
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I had a similar issue, but it was with my navigation lights, which is on a three way rocker switch. It turned out to be the switch (a friend who is a boat mechanic told me it was the switch, and he was right). My boat is about the same vintage (mine's a 1998) as yours, so maybe these rocker switches start to die after 21 years.
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Old 06-09-2019, 07:12 AM
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Good luck,these things make me want to sell my boat.Remember it usually something simple.
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Old 06-09-2019, 09:04 AM
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UPDATE:

OK, so I got out there again with a meter.

Also I should first mention, yes there are several other electrical issues:

1. VHF Radio is not turning on.
2. Hatch Hydraulic lift has stopped working, when switch is depressed I get a soft clicking sound, like when you try to start a car with a dead battery.
3. The bilge pump, as mentioned.

Left the three batteries charging overnight, measured them this morning, all were 13.3 volts, 5.05 amps.

Tested the leads to the bilge pump with the manual (console) switch in the ON position:

Voltage between the leads: 9.01 volts. Current was under an amp, almost unmeasurable.

Also tested continuity. Negative bilge pump wire to negative battery post: good. Positive pump wire to positive battery post: Good

Also tested the three breakers. The terminals looked good inside of their container, no rust or corrosion. There are 3 on that bilge pump panel, Main (40amp) Front (10 amp) Aft (10 amp).
Got good continuity on all three breakers. Tested voltage on both posts of each breaker to battery's negative post, got 12.4-13 volts on all three of them. So it does not sound like the breakers are bad.

So the problem appears that I am getting under 12 volts to the bilge pump. There is something leaking somewhere, could it be responsible for the other electrical issues?

Could it be the manual dash switch? I could test that next.
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Old 06-09-2019, 09:21 AM
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There should be two separate circuits feeding the bilge pump... the automatic and manual. The automatic circuit should come directly from the battery (+) post (or the battery switch post), through a fuse or breaker, to the float switch and then to the pump. The other circuit comes from a breaker on the main DC panel then directly to the motor (there may or may not be a fuse in this circuit too).

Based on your last post, it definitely sounds like you have an issue on the manual circuit somewhere. When you took those voltage measurements on the circuit breakers, was there any load on the system?? Do that test again and try to use your hatch lift and see if it affects the voltage you measure on the bilge breakers. That would indicate a problem more 'upstream' than your main panel, like your battery switch or some connection there.

What else works or doesn't work? It is only the things you listed that are having issues?
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Old 06-09-2019, 09:45 AM
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Yes, it looks to be wired as you describe, with the auto- and manual-wiring.

The engine hatch lift control and the VHF radio are not working. (Luckily it's stuck in the Up position) Engine hatch hydraulic motor makes a clicking sound when switch is depressed.

I can't really see where the wiring comes from to the bilge area. It runs inside of a plastic conduit along the keel toward the stern, then up the stern wall, then it seems to go left, but it joins with other wires. The breaker switches for the bilge pumps are up above the battery inside a little panel inside the engine compartment, near the front, opposite the stern. What's odd is they have much thicker red wires coming in and going out. I really can't see anything else regarding wiring because everything runs along the perimeter of the engine compartment and is hidden behind the engines.

So for automatic bilge operation, would it be Battery > Breaker > Bilge Pump? Would there be anything else in line of that?
And for Manual operation, Battery > Breaker > Dash Switch > Bilge Pump?
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Old 06-09-2019, 09:54 AM
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Originally Posted by bluelair View Post
So for automatic bilge operation, would it be Battery > Breaker > float switch > Bilge Pump? Would there be anything else in line of that?

And for Manual operation, Battery > Battery switch > Master breaker > Bilge Breaker > Dash Switch > Bilge Pump?
FIFY, but yes, basically that's it.. Note that those two bilge breakers would be different breakers, as one is fed direct from battery and one is fed from your regular DC panel with all the rest of your accessories.
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Old 06-09-2019, 10:06 AM
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OK, thanks. So if that's all that's in line in these circuits, and I know I have good voltage coming out of the bilge breaker (13v) but low voltage (9v) coming TO the bilge pump wiring, then it would have to be a bad switch causing that? Or something else perhaps in the wiring itself?

Would it be better to run a new wiring lead from the bilge breaker directly to the bilge pump, install an automatic bilge pump (bypassing the float switch) and just call it a day? Do I need to exercise any special precautions for something like this, since it is down in the engine compartment near the fuel?
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Old 06-09-2019, 10:21 AM
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Of you have good juice going into and out of the breaker, but low juice at the bilge pump itself, then Iíd think you have corrosion in that line. For shits and grins, run a new 12v+ from the breaker to your pump. Just lay it out there at this point (as a test, donít tuck it all away or run it under the deck yet). Use the existing ground wire. I bet she turns right on. Thatíll prove that your 12v+ lead is bad.

Iím assuming your vhf, hatch, and bilges arenít sharing Wires? Maybe your hatch and vhf are?
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Old 06-09-2019, 10:54 AM
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Regrettably your boat lives in a very corrosive environment. Yes, you must clean and regularly maintain every connection with emphasis on the battery terminals and wires. 12v systems are extremely sensitive to non-perfect connections due that voltage is low (12v) to start with. After connectors, you need to inspect the wires themselves. All corroded tarnished or black looking wires need to be replaced. Your biggest enemy is voltage drop due to resistance. Clean and tight connections are friend.
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Old 06-09-2019, 11:57 AM
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Originally Posted by wdlfbio View Post
Of you have good juice going into and out of the breaker, but low juice at the bilge pump itself, then Iíd think you have corrosion in that line. For shits and grins, run a new 12v+ from the breaker to your pump. Just lay it out there at this point (as a test, donít tuck it all away or run it under the deck yet). Use the existing ground wire. I bet she turns right on. Thatíll prove that your 12v+ lead is bad.

Iím assuming your vhf, hatch, and bilges arenít sharing Wires? Maybe your hatch and vhf are?
I haven't really checked the wiring for those others yet....I know the VHF plugs into a small fuse and distribution panel inside of the console, It could be power to that fuse console is bad, will check that next.

The hatch motor is in the engine bay, near the batteries. I will try that next.

I did connect the bilge pump to the battery directly, it spun right up, but I will try it with the ground wire as you suggested to confirm that is not the source of the resistance.

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