START/STOP PROBLEM

[Bob.Doubles]

My Vetus 4.15 has suddenly developed a start and stop problem. I turn the key and get a very low alarm, very dim lights on the instruments and it will not turn the engine over. If I move the key backwards and forwards a few times, the alarm gets loud, the lights get bright and it will start no problem. Then it won't stop using the key. If it starts once, it won't start again without giggling the key again. I have tried a different ignition switch but it makes no difference. I have changed the stop/start relay, and I replaced those useless 12 way connector blocks some time ago. But I obviously have a bad connection somewhere. Any ideas?

[Tony Brooks]

The fuse that Vetus often hide in or close to the plastic "box" on or behind the rocker cover.

[Bob.Doubles]

Thanks. The fuse is not blown, but I guess it might be a poor contact.

[Tony Brooks]

11 minutes ago, Bob.Doubles said:

Thanks. The fuse is not blown, but I guess it might be a poor contact.

 

I was thinking poor contact caused by a loose fuse holder damaged by engine vibration. A silly place for the fuse. That is easy to check.

 

It sounds like a loose or dirty contact somewhere, are you aware that some boats have another main harness multi-plug close to the control panel.

 

Engine battery master switch faulty - especially if t has a removable plastic key (usually red). If so put a screwed up ball of paper under the key and reinsert it, or put all the cables on one terminal.

 

Take the engine battery terminals off (neg first), clean the mating surfaces to bright metal, dress with Vaseline or terminal dressing and refit.

 

 

Edited September 9, 2023 by Tony Brooks

[Bob.Doubles]

I've cleaned the battery terminals already.

 

Yes, I wondered about the battery master switch, but it seems a bit unlikely.  Why do you say 'especially if has a plastic key'? 

[Tony Brooks]

14 minutes ago, Bob.Doubles said:

I've cleaned the battery terminals already.

 

Yes, I wondered about the battery master switch, but it seems a bit unlikely.  Why do you say 'especially if has a plastic key'? 

 

Because master switches with plastic keys, especially red one, are well known for being trouble.  They cause all sorts of intermittent faults.

 

What happens is that the copper contacts are mounted on thermo-plastic so if they heat up the plastic softens, collapses, so the contact no longer make godd contact all the time.

[Bob.Doubles]

Thanks - that all makes sense. I have a few things to try now. If you think of anything else, let me know! 

[Tony Brooks]

The diagnostic process:

 

It seems three circuits are affected, the stop circuit, the starter energisation and the instruments/warning lamps. The stop may or may not be part of the  instrument/w. lamp circuit.

 

The common thing to all these is the ignition switch, but you have changed that, so it goes to the bottom of the possibility list.

 

Providing all the terminals on the ignition switch are tight, clean and properly crimped to their cables, we need to move further back towards the batteries.

 

Working back, the first thing you may or may not come to is the multiway plug, but you have dealt with that. Next the fuse for the engine electrics, but you have checked that (I presume).

 

Finally, we end up on the main starter motor battery terminal that is always at 12V+ as long as the master switches are turned on. It will be a thinish cable, usually with an eye terminal or a 9mm blade.

 

Moving back towards the batteries you typically, on a modern boat, come to the master switch, and then the battery terminals. You say that you have cleaned the terminals, but did you clean then to BRIGHT shining metal? You can get a coating of exceptionally hard black oxide on them.

 

If all that is correct, then all that is left is the negative side. There will be a negative "feed" to the instrument panel, so make sure ALL of that if OK. Make sure the main engine battery negative runs to the engine block (often a negative terminal on the starter) and on to the boat hull/engine bed.

 

The negative is usually common to the instruments, but the warning lamps, stop and starter solenoid all run to negative on the block (usually) so they should not be affected by a problem on the instrument panel negative, hence me suspecting a positive fault. Note the instrument usually have a negative connection in their own right, but if that failed all you would see is funny reading.

 

 

Edited September 9, 2023 by Tony Brooks

[Tracy D'arth]

What did you use as a replacement ignition switch?

[Martin Nicholas]

Blade fuses, especially those subject to vibration, can crack at the junction of the "wire" and the blades. The fuse mounted on the engine of my old generator did this more than once during its 11000 hour lifetime.

[Bob.Doubles]

15 hours ago, Tracy D'arth said:

What did you use as a replacement ignition switch?

I had a spare given to me a while ago. Of course, this spare may have problems but, on the balance of probability, they would not be identical to the issues presented by the original switch.

4 hours ago, Martin Nicholas said:

Blade fuses, especially those subject to vibration, can crack at the junction of the "wire" and the blades. The fuse mounted on the engine of my old generator did this more than once during its 11000 hour lifetime.

The fuse on the Vetus is a cartridge fuse in a panel mount. It all looks fine (and, since the engine will run with some coaxing) it is fine.

15 hours ago, Tony Brooks said:

The diagnostic process:

 

It seems three circuits are affected, the stop circuit, the starter energisation and the instruments/warning lamps. The stop may or may not be part of the  instrument/w. lamp circuit.

 

The common thing to all these is the ignition switch, but you have changed that, so it goes to the bottom of the possibility list.

 

Providing all the terminals on the ignition switch are tight, clean and properly crimped to their cables, we need to move further back towards the batteries.

 

Working back, the first thing you may or may not come to is the multiway plug, but you have dealt with that. Next the fuse for the engine electrics, but you have checked that (I presume).

 

Finally, we end up on the main starter motor battery terminal that is always at 12V+ as long as the master switches are turned on. It will be a thinish cable, usually with an eye terminal or a 9mm blade.

 

Moving back towards the batteries you typically, on a modern boat, come to the master switch, and then the battery terminals. You say that you have cleaned the terminals, but did you clean then to BRIGHT shining metal? You can get a coating of exceptionally hard black oxide on them.

 

If all that is correct, then all that is left is the negative side. There will be a negative "feed" to the instrument panel, so make sure ALL of that if OK. Make sure the main engine battery negative runs to the engine block (often a negative terminal on the starter) and on to the boat hull/engine bed.

 

The negative is usually common to the instruments, but the warning lamps, stop and starter solenoid all run to negative on the block (usually) so they should not be affected by a problem on the instrument panel negative, hence me suspecting a positive fault. Note the instrument usually have a negative connection in their own right, but if that failed all you would see is funny reading.

 

 

This is very helpful as a check list. I need to run through it all in a logical way next time I'm on the boat.

[Tracy D'arth]

6 minutes ago, Bob.Doubles said:

I had a spare given to me a while ago. Of course, this spare may have problems but, on the balance of probability, they would not be identical to the issues presented by the original switch.

The fuse on the Vetus is a cartridge fuse in a panel mount. It all looks fine (and, since the engine will run with some coaxing) it is fine.

This is very helpful as a check list. I need to run through it all in a logical way next time I'm on the boat.

The spare switch could well have the same fault as yours!  The failure of a switch is usually that it doesn't switch on!

[MtB]

3 hours ago, Tracy D'arth said:

The spare switch could well have the same fault as yours!  The failure of a switch is usually that it doesn't switch on!

 

This was my first thought too on reading the switch was 'replaced'.

 

If not a brand new switch in sealed makers packaging, then the one the OP fitted could have been removed for the exact same failure. Identical mechanical things tend to all fail in the same way.

 

I get this with boiler repairs too. A customer calls with a fault that for all the world sounds like <whatever>, I tell them what part I think needs changing and they tell me they've already changed that bit. On careful questioning it sometimes turns out they fitted one they found in the garage, or salvaged from a neighbour's scrapped boiler, or second hand 'reburbished' by God knows who, and a brand new part works. 

 

 

[Tracy D'arth]

20 minutes ago, MtB said:

 

This was my first thought too on reading the switch was 'replaced'.

 

If not a brand new switch in sealed makers packaging, then the one the OP fitted could have been removed for the exact same failure. Identical mechanical things tend to all fail in the same way.

 

I get this with boiler repairs too. A customer calls with a fault that for all the world sounds like <whatever>, I tell them what part I think needs changing and they tell me they've already changed that bit. On careful questioning it sometimes turns out they fitted one they found in the garage, or salvaged from a neighbour's scrapped boiler, or second hand 'reburbished' by God knows who, and a brand new part works. 

 

 

I learnt long ago that if a part is replaced because it is faulty then the new part is possibly also faulty. I have known starter motors to be changed repeatedly because they were all faulty from new.

I remember Ford transit engines that would burst the oil filter, a new one would work for a while, until the pressure release valve seized closed again.

[Bob.Doubles]

I'm sure you are all absolutely correct about the 'replacement' ignition switch, but given the cost of Vetus spares, there are a number of things I want to try first. Unless anyone has an idea for testing an ignition switch...

[Tracy D'arth]

11 minutes ago, Bob.Doubles said:

I'm sure you are all absolutely correct about the 'replacement' ignition switch, but given the cost of Vetus spares, there are a number of things I want to try first. Unless anyone has an idea for testing an ignition switch...

Just short the wires together to the one that is always live, big spade, and see if everything then works. If it does, its the switch.

[Bob.Doubles]

40 minutes ago, Tracy D&#x27;arth said:

Just short the wires together to the one that is always live, big spade, and see if everything then works. If it does, its the switch.

Thanks, I'll try it.

[MtB]

Just now, Bob.Doubles said:

Thanks, I'll try it.

 

 

Are you a bellringer, with Bob Doubles for a boat name?

 

 

[Bob.Doubles]

Yes, I am a bellringer, although these days I can cruise Bob Doubles better than I can ring it!! 

[MtB]

2 hours ago, Bob.Doubles said:

Yes, I am a bellringer, although these days I can cruise Bob Doubles better than I can ring it!! 

 

Do come and ring with us if you ever come down to the K&A! We get occasional bellringing boaters visiting in passing, who are always made very welcome.

 

 

[Bob.Doubles]

Thanks - which is your tower?

[Tony Brooks]

23 hours ago, Bob.Doubles said:

I'm sure you are all absolutely correct about the 'replacement' ignition switch, but given the cost of Vetus spares, there are a number of things I want to try first. Unless anyone has an idea for testing an ignition switch...

 

Wot Tracy said, but I know I wrote  a longish piece about doing this a few weeks ago, but can't find it right now