Windlass troubleshooting

[Sea Change]

My windlass is intermittently, and increasingly, not working. Generally I hear a click from the relay box but nothing moves.
Occasionally it does burst in to life but it's slower than I would expect and can be stalled out easily.

It's wired to its own battery which charges using 50mm² cables from the engine. I'm getting around 14.2v at the windlass battery when the engine is running.

This morning I decided to troubleshoot with a multimeter whilst attempting to lift the anchor, and noticed that on the terminals of the relay box I was seeing the voltage fall to zero when I pressed the button.

I've done the obvious things- taken apart accessible connections and cleaned up, sprayed with contact cleaner, reassembled. I replaced the battery a few weeks ago. I try to let the engine run for a few minutes before using the windlass, to bring the voltage up.

Next steps? I have a spare relay box so I could try swapping those over. I could remake the crimped eyes on all the cables. I also have oodles of spare 50mm² cable so could swap out entire lengths.

All of the above involves wriggling in to a small, awkward, hot space. So I'd like to target the things that are most likely to actually work.

Based on the above symptoms, where should I start?

 

[NormanS]

I would check the brushes and commutator.

 

[wonkywinch]

If the voltage at the relay terminals falls to near zero when the load is applied then the problem is in the cable/connection to that point. Undo the nuts holding the cables to the studs, take apart, soft wire brush (I use a little brass wire one) the flats and connector studs.

Reassemble and do the same for the other ends of those cables wherever they are fed from. Be very careful not to let cables touch each other or anything metal/electrical whilst working.

If you had a solid 12-14v at the relay when cranking but the motor was weak then I would check the brushes etc but the supply dropping off under load indicates a supply issue.

The cable, studs, spade connector, washers etc are all made from different metals and dissimilar metals cause galvanic corrosion and present a higher resistance to the load and this shows as the symptoms you describe.

Once done, I give the terminals a light smear of vaseline for future protection.

 

[Tranona]

If it has a Lofrans control box like one of these lofrans.com/product/78-control-boxes-switchb/5034-solenoids the contacts tend to stick so if you have a spare fit that and clean all the terminals as suggested.

 

[OCuea]

I have read on here so many times that the voltage should be measured when the current draw is called for but did not post anything until wonkywinch did because the OP said they had cleaned everything up. I learned so much of what I know from this forum. Would it be an idea to use clean crocodile clips to temporarily hook up nearby battery to windlass and if it works you know you have corrosion creeping down your normal wires and then you have a rewrite job

 

[wonkywinch]

I have read on here so many times that the voltage should be measured when the current draw is called for but did not post anything until wonkywinch did because the OP said they had cleaned everything up. I learned so much of what I know from this forum. Would it be an idea to use clean crocodile clips to temporarily hook up nearby battery to windlass and if it works you know you have corrosion creeping down your normal wires and then you have a rewrite job

You can't use croc clips for this purpose unless you mean car jump leads due to high current.

The "corrosion creeping" statement is inaccurate. There are submarine and phone cables that are more than a hundred years old still working. Unless a cable end was submerged I can't see any way corrosion would creep past where the insulation was cut back to.

 

[OCuea]

You can't use croc clips for this purpose unless you mean car jump leads due to high current.

Thr "corrosion creeping" statement is inaccurate. There are submarine and phone cables that are more than a hundred years old still working. Unless a cable end was submerged I can't see any way corrosion would creep past where the insulation was cut back to.

I meant jump leads that have crocodile clip terminals. I have had 4 windlasses in my time. Would the submarine cables be tinned and the insulation etc super excellent? A few years ago a mate asked me to look at his failing pullpit led nav light. 13volts measured but less when switched on and current called for. Domestic cable had been used and the copper was green for about 10 feet back so a rewire was done and light worked again. He sailed so his pullpit and nav light got wet alot and the hella marine nav light was obviously not waterproof. I thought I was agreeing with your statement ‘problem is in the cable/connection ’

 

[wonkywinch]

I meant jump leads that have crocodile clip terminals. A few years ago a mate asked me to look at his failing pullpit led nav light. 13volts switched off, less switched on. Domestic cable had been used and the copper was green for about 10 feet back so a rewire was done and light worked again. He sailed so his pullpit and nav light got wet alot and the hella marine nav light was obviously not waterproof. I thought I was agreeing with your statement ‘problem is in the cable/connection ’

No problem but can I ask how the "copper was green for about 10 feet back"? Presumably it was uninsulated cable otherwise you wouldn't be able to see the patination. The marine nav light should be waterproof but if somebody wired it with domestic cable (usually solid core and unsuitable for the vibrations of a boat) then perhaps they were just as gash with the cable gland/seal?

 

[OCuea]

No problem but can I ask how the "copper was green for about 10 feet back"? Presumably it was uninsulated cable otherwise you wouldn't be able to see the patination. The marine nav light should be waterproof but if somebody wired it with domestic cable (usually solid core and unsuitable for the vibrations of a boat) then perhaps they were just as gash with the cable gland/seal?

It was insulated. I kept cutting back hoping to find copper colour. It was mutistrand, not solid core like domestic cooker cable. I convinced him to buy tinned and job was sorted. The rubber gasket on hella nav light was old and cracked. Vaseline had been used on bulb terminals but they used wrong cable and did not seal the ends obviously

 

[wonkywinch]

Understood. So not "corrosion creeping down your normal wires" but a bodge that came back to bite

 

[OCuea]

Understood. So not "corrosion creeping down your normal wires" but a bodge that came back to bite

Yes but not my wires or my bodge or even the owners because it was second hand to him. I always used to use tinned wire and overspecification and properly fused and I used silicon grease to keep things better than ip67. If feeling flush I would use nice flexible silicon insulated wire too - bit pricey.

 

[Sea Change]

Update:
I've swapped out the relay box. Windlass sprang to life eagerly, twice. Then back to just a click. Urgh. This was under no actual load, with the clutch disengaged (I'm currently at anchor). Voltage was reading 12.6v then falling to zero when I press the button.

The 'new' relay box came off another boat, so it's not impossible that it too is faulty.

Time to open one of them up, do you think?

 

[Sea Change]

This is what I've found. Slight pitting on the contacts but otherwise looks very clean inside.
I'll put it back together and see if it's actually making a connection.

Edit: making a perfect connection. Time to open up the windlass itself then...

 

[wonkywinch]

This is what I've found. Slight pitting on the contacts but otherwise looks very clean inside.
I'll put it back together and see if it's actually making a connection.View attachment 190615

Edit: making a perfect connection. Time to open up the windlass itself then...

Did you follow my suggestion in post #3?

Still stand by my thought that there is a problem with the supply connection. As you've removed/reconnected the relay end, that will be OK. How is the negative connector and the thick cables at the other (battery) end of the supply.

If volts go to zero on activation, there is either a very high current load (hundreds of amps which will manifest itself as heat and/or smoke) or, my view, resistance in a joint caused by galvanic corrosion causing the high load of the windlass to pull the 12v rail down to zero.

 

[Sea Change]

And another update. Turns out the wired control unit is knackered. If I unplug it and use a bit of wire to activate the relay, everything is working perfectly.

One of the soldered connections on the little PCB had come loose and was shorted out. I realised I had a problem when I was measuring a voltage on both positive terminals on the windlass motor!

Now, I wonder how much Lofrans will want to charge me for a little box with two micro switches inside...

Edit: spoke too soon, see below

 

[Sea Change]

Did you follow my suggestion in post #3?

Still stand by my thought that there is a problem with the supply connection. As you've removed/reconnected the relay end, that will be OK. How is the negative connector and the thick cables at the other (battery) end of the supply.

If volts go to zero on activation, there is either a very high current load (hundreds of amps which will manifest itself as heat and/or smoke) or, my view, resistance in a joint caused by galvanic corrosion causing the high load of the windlass to pull the 12v rail down to zero.

There is a 100A breaker in the circuit so I'm not getting any dead shorts.

I've been measuring between the middle terminal and the other two (the up and down). The relay is closing perfectly, hence the zero volts, but I don't know where that power is going.

Oh and my 'fix' was very short lived. Even taking the dodgy control unit out of the picture, it only worked a few times and then stopped again. Humph.

 

[wonkywinch]

How/where are the heavy duty power leads connected to the supplying battery? If there is also a 100A breaker in the circuit, have you removed, cleaned and refitted the spade terminals to that? Are the spades all still securely crimped to the cable?

I am convinced from the start you have resistance in those supply lines. Corrosion and/or loose connection. It will only show up when you try to draw loads of amps down it.

 

[Sea Change]

The supplying battery is about two feet away from the windlass. The breaker is at the battery.
I guess I'm just going to have to go through each component until I find the fault.

 

[Sea Change]

I'm still getting a drop to zero volts on *both* the up and down terminals when I trigger the relay.
That can't be right?

 

[wonkywinch]

I did offer a suggestion in post #3. Just work your way logically from the supply (battery) to the demand (motor). If one connector is corroded, clean them all.