sshortcircuit Posted April 26, 2012 Share Posted April 26, 2012 I trust you appreciate that once you do get your problems sorted that with split charge relays it takes hours of driving to charge the leisure battery/s. The alternator looks at the starter battery and once it is charged it reduces considerably leaving a minimum charge for the leisure batteries. Best before you venture to have your leisure batteries well charged and if need be use a hookup/generator to top up. Alternatively you can fit relays/B2B chargers to increase charge when engine running. Good luck with your fault finding Link to comment Share on other sites More sharing options...
Robinhood Posted April 26, 2012 Share Posted April 26, 2012 ....well, the diagram was largely for illustration, it being a 2004 Bessacarr; the earliest I could pull up. The concepts will be entirely the same on a 2000 van, however, and I wouldn't be at alI surprised if the wiring colours are the same (but they may not be). I'm going out on a limb here, but the other posts in the thread all align with my understanding. Keith has relied on (and decribed correctly) the diagram, I will be a little more detached given the possibility of different layout and wiring colours. I believe there will be two relays (most probably secured under the plastic engine cover) within the engine bay. These will be the split charge, and fridge relays respectively. The EMC relay is likely to be in the habitation area (and in your case is likely to be associated with, if not in the PSU (distribution) unit). It plays no further part in our discussion, but, if it operates and switches the habitation power off when the engine is running, then we can assume that the alternator sensing circuit is working (at least down this leg!). It now makes sense to identify which of the two relays in the engine bay is which. There are a couple of ways in which this could be determined. (though if the wiring is the same colour as in the diagram, there is an obvious third) If you have a light on your fridge denoting 12V working, then each relay could be removed in turn and (with the engine running) the one that is removed when the light is out is the fridge relay. Alternatively, the output from both relays should feed fairly quickly into a fuse holder with three or four fuses. Of the two relay outputs, the one that feeds the lower value fuse (probably 15amp) is likely to be the fridge, and the other (probably 20 amps) the leisure battery/habitation feed. Check both the input and output sides on both these fuses to earth for around 14.5v with the engine running. If you don't get a reading in all 4 places, you've started to identify the issue. If both inputs are zero, physically check the alternator sensing (field) circuit to both relays; If this looks OK, then unlikley as it might be, either the alternator, or both relays are probably duff. If one fuse input is zero, switch the relays over and try again (hopefully identifying a duff relay by reversing the ouput that is zero) If the inputs are OK but one or both outputs are zero, then one or both fuses are suspect (trust the meter, not your eyes!). If there is voltage across the output side of both fuses, then it is time to check the supplementary (20 amp) fuse which will probably be somewhere near the leisure battery. With the engine running, check both sides of this fuse to earth. If you don't get voltage at the input side, then the wire is broken somewhere between the fuse in the engine bay and here. If that is OK, but you don't get voltage at the output side, then the fuse is dead. There is little else I can think of that could result in no charging to the leisure battery, as the circuit is relatively simple. Link to comment Share on other sites More sharing options...
Brambles Posted April 26, 2012 Share Posted April 26, 2012 Robin - I have thought of one you might have missed - check there is 0 volts between the negative terminal of battery and the chassis. If the chassis connection has been left off for any reason or broken for the leisure battery and all habitation negative connections return to the battery terminal, then it is possible when trying to charge from the engine there is no return path. The voltage on the negative terminal will rise to a volt or two when the engine is started. Link to comment Share on other sites More sharing options...
Robinhood Posted April 26, 2012 Share Posted April 26, 2012 Brambles - 2012-04-26 10:16 PM Robin - I have thought of one you might have missed - check there is 0 volts between the negative terminal of battery and the chassis. If the chassis connection has been left off for any reason or broken for the leisure battery and all habitation negative connections return to the battery terminal, then it is possible when trying to charge from the engine there is no return path. The voltage on the negative terminal will rise to a volt or two when the engine is started. Jon, I agree with the additional potential (no pun intended) problem. So, an additional early test might indeed be also to continuity check between the negative terminal of the leisure battery and the hassis. Link to comment Share on other sites More sharing options...
Lorpet Posted April 30, 2012 Author Share Posted April 30, 2012 Hi, specifically Travelling Tyke and Robin Hood about the charging. I'm confused. The secto of the wiring duagram sent by Robin Hood shows the split charging relay with, the idle state, with the connection to an unused terminga and moving over to the Brown Blue wire on operation. The circuits in the Bessacarr 700 series and indeed my book on the E600 series with the idle condition showing the connection to the Blue Brown and moving to a disconnect when operated. This is the opposite to the actual wiring. Any views on this woud be appreciated. Now that the truth of the diagrams has been undermined, does any one know the circuit for the EMC relay. Lorpet Link to comment Share on other sites More sharing options...
Guest Tracker Posted April 30, 2012 Share Posted April 30, 2012 With respect Lorpet it seems that you don't really appear to understand your van's wiring so may I recommend that you take it to see a good auto electrician - preferably one who has seen a motorhome's wiring before if possible - who should very quickly and easily be able to diagnose and rectify your fault(s) and may well even save you money in the long run as well as much frustration? If you are able to remain with the van and watch what he checks and does that too may well stand you in good stead in the future? Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 30, 2012 Share Posted April 30, 2012 OK, I'll ask the idiot question. :-) Lorpet, what makes you think that the alternator is not charging the leisure battery? You haven't mentioned that it is/keeps going flat, or that you've recently had to replace it, so why do you suppose it isn't being charged while you are driving? You do seem very convinced that it isn't, so I assume something is giving you that impression. BTW, do you know the age of the battery? Could it just be old and dead, and unable to hold a charge, rather than not being charged? Link to comment Share on other sites More sharing options...
Robinhood Posted April 30, 2012 Share Posted April 30, 2012 Brian Kirby - 2012-04-30 9:22 PM OK, I'll ask the idiot question. :-) Lorpet, what makes you think that the alternator is not charging the leisure battery? You haven't mentioned that it is/keeps going flat, or that you've recently had to replace it, so why do you suppose it isn't being charged while you are driving? You do seem very convinced that it isn't, so I assume something is giving you that impression. BTW, do you know the age of the battery? Could it just be old and dead, and unable to hold a charge, rather than not being charged? ....if you check my first post, Brian, I implicitly asked this question, by emphasising the phrase if it isn't charging whilst driving. The follow-up has been posted in the spirit that this particular point had been checked. :-S Nonetheless, I'm coming to the conclusion that Rich's suggestion is the best - the problem should be simple for an auto electrician to diagnose and fix, and maybe Lorpet should try that route. For Lorpet: I'm certainly not convinced that the diagram and particularly the wiring colours are the same as your vehicle, but it really does show the simplicity of the circuit design, and demonstrates that fault finding, particularly if you have a meter, should be fairly simple. Over and above the advice already given, I can't add much more (other than the fact that the duty of the relays, as shown in the diagram, is to complete the fridge 12v, and leisure battery charging circuits respectively when the alternator is producing current, not break them as you seem to imply. (Though the action of an EMC relay or equivalent, which will not be in this particular circuit, but will probably be triggered by one of the feeds going back to the PSU, would be to break the overall 12v habitation circuit - but it should have no effect on the split charge and fridge circuits, which should be independent of EMC provision). Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 30, 2012 Share Posted April 30, 2012 Robinhood - 2012-04-30 9:55 PM.........................if you check my first post, Brian, I implicitly asked this question, by emphasising the phrase if it isn't charging whilst driving. The follow-up has been posted in the spirit that this particular point had been checked. :-S ....................... I know, and I agree Robin, but I just wondered if the point may have been missed as it was implied rather than directly stated. So, I just thought I'd try being less subtle.................see? :-) However, if Lorpet is unfamiliar with these circuits, and is finding them confusing on first acquaintance, I think the advice to get help from an auto electrician (or even better, if he can find a decent dealer with one, an electrician who is fully familiar with motorhome wiring) is the safest path for him to follow. 12V may sound "safe" to fiddle with, but fully charged batteries pack quite a punch and unprotected wiring circuits will heat up very quickly if the wrong bits are put together. Better to spend money on expert help, than to set fire to the van! Firms carrying out full habitation servicing on motorhomes should have an appropriate person around. Link to comment Share on other sites More sharing options...
Robinhood Posted April 30, 2012 Share Posted April 30, 2012 Brian Kirby - 2012-04-30 10:15 PM I know, and I agree Robin, but I just wondered if the point may have been missed as it was implied rather than directly stated. So, I just thought I'd try being less subtle.................see? :-) ....bl**dy hell! Me being called subtle?! There's a first time for everything. 8-) Link to comment Share on other sites More sharing options...
Lorpet Posted May 3, 2012 Author Share Posted May 3, 2012 Well, after a load of mucking about and puzzling over the circuit diagram I conclude that it is wrong. I went to the length of changing the relay to a five pin type and added a wire to the idle contact which showed 12V on it but zero when the engine was running. Exactly the opposite to that shown on the diagram. Going to the one provided by Robin Hood, it all worked out fine. I now have 12-13.5v at 5A going into the leisure battery form the alternator. Somewhere back in time I must have blown the fuse but not having the correct diagram it was impossible to trace the fault, not knowing there was a fault there in the first place. At least it seems to be corrected now. Out there now are Owner's Handbooks with bum information, shame on Swift. Thanks for all the help and support Lorpet Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 3, 2012 Share Posted May 3, 2012 It's good to know your leisure-battery is now receiving charge from the alternator, but 12V-13.5V seems unusually low. Normal expectation (as has been advised previously) would be 14V-14.5V with the motorhome's engine running, with the same voltage being delivered to the starter-battery. Are you measuring the voltage across the terminals of the leisure-battery? Link to comment Share on other sites More sharing options...
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