Solenoid on negative

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Elemental

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I have a VP 2003. Last week, twice, I pressed the starter only to be greeted by silence... I've tracked the problem to a relay/solenoid that is connected to the negative side of the starter battery. A smart tap with a hammer generally solves the problem... It's not ideal though :(

What I'm puzzled about is what this relay is for. I'm surmising that it connects the battery negative to the starter circuitry during the starting process, but why did VP bother with it. This is a standard 2003 installation - no saildrive. I'm sort of minded to just bolt the negative to the engine block somewhere (a replacement is £112) - that would work wouldn't it? But there must have been a reason for it's installation in the first place - the unit has a big yellow sticker warning of a non-standard negative and referring the reader to the manual...
 
It is an earthing relay . As you realise

It earths ( connects to negative) the engine block during preheating and cranking, otherwise all the engine electricals have insulated negative connections.

It is shown in the wiring diagrams in the manuals

Dunno why its fitted to some but not others. Thought, but obviously wrongly, that it was only fitted to installations with sail drives to help prevent corrosion.

Can't think of any reason why you should not make a permanent negative connection ~~ maybe someone else can.
 
You could earth the engine directly as said or you could use a starter solenoid from a 70's car (mini, mk1 escort) that uses an inertia bendix starter (about a £10).
 
As when the engines left the factory they did not know what transmission would be fitted they would all be built capable of being fitted to any transmission.
2000 series electrics are a nightmare to identify without seeing them have a look in the parts book and you will see.
 
scottie said:
As when the engines left the factory they did not know what transmission would be fitted they would all be built capable of being fitted to any transmission.
2000 series electrics are a nightmare to identify without seeing them have a look in the parts book and you will see.
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But they dont all have 2 pole electrics and an earthing relay. Some have a single pole system with the block used as the permanent negative connection.
 
MoodySabre said:
That's how my 2003 is.
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So, I'm left with two/three questions.
1. Why did Beneteau opt to fit the two pole option on my boat
2. Do I run any risk of corosion if I just connect the block to the starter battery. If not, where's the best place to connect the -ve (it's got to pass cranking amps)
 
cant answer the first question

on the basis that many or even maybe most dont have an isolated negative system I'd not expect any corrosion problem.

The one of the starter mounting bolts would be a good place if the existing cable reaches. Or to wherever the earthing relay is connected at present. You could even just move it to the other terminal of the relay and leave that in position
 
Don't Beneteau usually include a negative isolator switch in their wiring? The relay on the engine might be related to their thought processes re needing a negative isolator.
 
An isolated negative system is very common on aluminium boats. It does reduce the risk of corrosion problems even on fiberglass boats.
It is a superior system and I would not change it back to an earthed engine block. The hard work is in finding 2 wire sensors etc and this has been done. The relays are cheap and easy to replace. The higher the relay rating the better, but inexpensive, large case, automotive relays of 100a or even 60a so seem to survive surprisingly well in this application.
Double check the relay has failed often the engagement mechanism (which is usually a small 10a relay wired to the start switch) fails. I usually replace this automatic system with a switch.
 
noelex said:
An isolated negative system is very common on aluminium boats. It does reduce the risk of corrosion problems even on fiberglass boats.
It is a superior system and I would not change it back to an earthed engine block. The hard work is in finding 2 wire sensors etc and this has been done. The relays are cheap and easy to replace. The higher the relay rating the better, but inexpensive, large case, automotive relays of 100a or even 60a so seem to survive surprisingly well in this application.
Double check the relay has failed often the engagement mechanism (which is usually a small 10a relay wired to the start switch) fails. I usually replace this automatic system with a switch.
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The Op quotes a figure of £112. It might be cheap to you. It would not be to me, especially if there was not a compelling reason to replace it.

A Volvo replacement should fit directly on the mounting bracket and the electrical connections should fit as well. That may not be the case if another make solenoid is used. If alterations to the mounting or electrical connections are necessary it also ceases to be easy to fit.

Having said that Volvo dont make these theings themselves. So it should be possible to find one still wearing its original colours and hopefully less expensive.

A temporary fix would buy some time to find a direct replacement at a more reasonable price. Bosch perhaps.

The same relay energises the main solenoid on the starter motor. If the OP diagnosis is correct its not the intermediate relay that's at fault.
Worth double checking though.
 
VicS said:
The Op quotes a figure of £112. It might be cheap to you. It would not be to me, especially if there was not a compelling reason to replace it.

A Volvo replacement should fit directly on the mounting bracket and the electrical connections should fit as well. That may not be the case if another make solenoid is used. If alterations to the mounting or electrical connections are necessary it also ceases to be easy to fit.

Having said that Volvo dont make these theings themselves. So it should be possible to find one still wearing its original colours and hopefully less expensive.

A temporary fix would buy some time to find a direct replacement at a more reasonable price. Bosch perhaps.

The same relay energises the main solenoid on the starter motor. If the OP diagnosis is correct its not the intermediate relay that's at fault.
Worth double checking though.
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I have checked the intermediate relay and it's working fine. I have also checked voltage on the wire from there to the relay and that looks fine too. A gentle tap on the relay fixes the problem so I'm happy I know what the problem is.

£112 (plus delivery) is the Volspec price and seems extortionate (but this is a Volvo). I think, what I'm going to do is 'jury rig' a direct negative connection and try and track down a replacement. It seems (from other sites) that it's a badged Valeo "#CEY 113". I can't find a UK supplier but a belgian one is 135.27 Euros! I'm not at the boat (or even near it) so can't check, bit what chance I can pull it apart and 'unstick' it?
 
Volvo spares are notoriously expensive. There are much cheaper relays that will work fine. There are enough alternatives available that a model with the same size and type of electrical connectors should be available. If this is the case then its only a few minutes to change.
A photo of the original part would help.

I think the reduced chance of corrosion problems warrants the small cost and difficulty in replacing it. The original builder obviously agreed to fit the solenoid and associated wiring in the first place, together with replacement dual wire senders and isolated alternator (its possible the alternator was isolated as standard, but its unlikely the senders were)
 
noelex said:
Volvo spares are notoriously expensive. There are much cheaper relays that will work fine. There are enough alternatives available that a model with the same size and type of electrical connectors should be available. If this is the case then its only a few minutes to change.
A photo of the original part would help.

I think the reduced chance of corrosion problems warrants the small cost and difficulty in replacing it. The original builder obviously agreed to fit the solenoid and associated wiring in the first place, together with replacement dual wire senders and isolated alternator (its possible the alternator was isolated as standard, but its unlikely the senders were)
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Its a standard Volvo configuration, but so is the single pole system.

It'll be part of the engine package not something retro fitted by the boat builder.

However in support of your claim:
There are much cheaper relays that will work fine. There are enough alternatives available that a model with the same size and type of electrical connectors should be available. If this is the case then its only a few minutes to change.​
I suggest you look at the wiring diagram in the 2003 owners manual and also at the parts catalogue and then find a few of these alternatives for the OP to consider.

I have been trying but so far failed !

What are these corrosion problems that will be reduced
 
There are not too many ways to wire a relay, but if anyone can force you to use an expensive branded part it would be Volvo.
Unfortunately my internet connection on the boat is way too slow to download a parts manual at the moment
There is some difference of opinion about the benefits of negative isolation on fibreglass boats. I have read corrosion experts describe is as anything from ‘overkill’ to ‘essential’. I suspect given the number of fibreglass without this system I think the truth is closer to former than the latter, but overkill is never a bad thing when it comes to boats and corrosion.
I believe Jeanneau did this with many of there earlier boats. Whether done by the engine manufacturer or builder they obviously felt the extra expense was justified
Given the system is already installed like this I would maintain this.

BTW there was a very similar thread last year
http://www.ybw.com/forums/showthread.php?t=255538&highlight=didn%92t+imply+ordinary+20A+suitable
 
Sea_Spray said:
Attached.

The white powdery material is salt, from when the shaft seal was leaking (and salty spray was being thrown around while the prop was turning). I've since replace the shaft seal.
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I think Id get it off and clean up those manky terminals to give it another try.

You may find a clue to its real identity under the yellow label!

I dont see anything on the page that opens from Nolex's link that looks like an easy substitute although one of the other pages on the site has some that look hopeful.
I guess anything with a suitable current rating and an isolated negative will enable something to be cobbled together

Ideally it needs to fit the existing bracket as below but you may have to make up an alternative to #10 which is the link to the engine block.

2003relay.jpg
 
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