Figured out why washdown pump doesn’t work. Now what?

Apr 8, 2011
768
Hunter 40 Deale, MD
Last weekend while washing down the last bit of the anchor after a nice lunch break and swim the washdown pump suddenly stopped working. This evening I got back to the boat after work and had the time to try to figure out why, and I did. Tracing the power and ground wires I found the red power wire tied into the windlass power point. Then I noticed the inline fuse for the washdown pump had melted nearly in two. What appeared to be a glass fuse inside was broken in two and I easily tore the plastic fuse holder in two.
So should I just figure out the right size inline fuse and wire a new one in it place? Or should I be concerned about WHY the fuse blew and the fuseholder melted? And if so, what is my next step?
 

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Feb 10, 2004
3,918
Hunter 40.5 Warwick, RI
Connections melt down due to heat. The heat is generated by high resistance and current. The high resistance is usually due to a poor connection. The in-line fuse that you show are notorious for poor connections. I would replace it with a spade-type fuse in a water-proof housing. And keep an eye on it.
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I take it that red wired operates the pump, and not a relay that closes to operate the pump? Looks likea small wire to power the pump.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
The wrong solution is to just put a larger fuse into the circuit. The pump is rated for 10 amp max draw, so a 14 gauge wire fused at 15 amps should be adequate. The yellow connectors suggest it is current wired with 10 or 12 gauge wire. One of the connectors does not look like it has been properly shrink wrapped and heat sealed. This could be a source of corrosion leading to the scenario @Rich Stidger suggests.

See if you can find a manual for the pump online and check the recommended fusing size and wire size.
 
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jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Does anyone else see the irony in the circuit protection device burning up? :)

Is this pump on a dedicated circuit to the panel and its own circuit breaker, or does it share a circuit with other devices?
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Does anyone else see the irony in the circuit protection device burning up? :)

Is this pump on a dedicated circuit to the panel and its own circuit breaker, or does it share a circuit with other devices?
I think @Rich Stidger summed up the reason for it melting pretty well.

The OP said the pump is supplied off the windlass circuit and it has circuit protection, albeit, a poor method at the source of it's power.

The photos show connectors that are not well sealed so corrosion within the wires is quite possible and we don't know if the fuse was too large to protect the wire.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
the pump is supplied off the windlass circuit
Ah, yes. I can imagine why that was done. Agreed the old fuse hold was el-crapo.

The new fuse is expected to protect that entire branch, from the power tap to the pump and then to ground, so should open if current exceeds the motor's peak current, and, of course, the wire sized well in excess of that. Wire sizing should take into consideration the loop length of the wire, and the voltage drop one's willing to tolerate for that device. For a pump 10% is generally acceptable, and at 10A 14AWG is good for a 40' loop length.
 
Apr 8, 2011
768
Hunter 40 Deale, MD
So based on you input I’ll:
- get new pump
- check wire size for length of run and replace if necessary
- wire new pump getting rid of 2nd splice and ensuring corrosion protected connections
- add new fuse holder/fuse at location of blown one at 15a (shurflo recommendation too, and 14ga wire)

Question: Shurflo says use a slo blow fuse. Are blade fuses slow blow, or should I still use a quality inline slow blow fuseholder and crimp it carefully in place with corrosion protection?
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Before you purchase a new pump, are you sure the pump you have is dead?

I'd replace the wire anyway. It is a small expense and you know the wire will be good.

The slow blow is probably unnecessary and hard to find in an automotive style fuse. Shuflo recommends it for pumps to avoid blowing fuses. When the pump first starts, it can draw a lot of current for a split second. If you can easily find one, then by all means use it, but it is less critical than getting a good watertight fuse holder and terminals.

Also get some dielectric grease and place on the lugs for the fuse, helps to protect against corrosion.
 
Apr 8, 2011
768
Hunter 40 Deale, MD
First, THANK YOU for your responses. Job successfully completed:

- Replaced 11 year old pump, which now that it’s out appears to have corroded from inside out
- Cut out double splice and crimped marine butt connectors to pump wires & to circuit and heat shrinked (circuit wire is 12awg; pump wires are 14awg on total of 10 foot run; 20ft if you add both wires together)
- Wired in high quality waterproof BlueSea inline fuse connector, carefully crimped and applied heat shrink at each end. This was the best solution available between a hardware store and West Marine locally.
- Put in 15 amp Ancor slow blow fuse (per manuf instructions) with light dielectric grease applied

Thanks for all the responses. I’ll check on everything after using it a few times.
 

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Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
- Replaced 11 year old pump, which now that it’s out appears to have corroded from inside out
Nice job. And this is probably the reason the fuse melted. Where you able to determine the size of the old fuse?
 
Apr 8, 2011
768
Hunter 40 Deale, MD
Nice job. And this is probably the reason the fuse melted. Where you able to determine the size of the old fuse?
I wasn’t able to determine to size of the old fuse - plastic melted to it and too much trouble to separate.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
First, THANK YOU for your responses. Job successfully completed:

- Replaced 11 year old pump, which now that it’s out appears to have corroded from inside out
- Cut out double splice and crimped marine butt connectors to pump wires & to circuit and heat shrinked (circuit wire is 12awg; pump wires are 14awg on total of 10 foot run; 20ft if you add both wires together)
- Wired in high quality waterproof BlueSea inline fuse connector, carefully crimped and applied heat shrink at each end. This was the best solution available between a hardware store and West Marine locally.
- Put in 15 amp Ancor slow blow fuse (per manuf instructions) with light dielectric grease applied

Thanks for all the responses. I’ll check on everything after using it a few times.
Nice job. I hope it works for years and years!

I would be tempted to support that fuse holder in some way, even if its leads were just tie-wrapped to some other wires.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I had my wash down pump stop working and found it only needed help and turned the motor with tool and
been working fine over year.
Make sure wires are clean water proof .
Nick
 
Apr 8, 2011
768
Hunter 40 Deale, MD
Nice job. I hope it works for years and years!

I would be tempted to support that fuse holder in some way, even if its leads were just tie-wrapped to some other wires.
That’s a great idea. I’ll make that happen.
 
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