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gsvmtv
gsvmtv

Posted: Sun Jul 24, 2016 6:11pm

Post Subject: No charge from alternator

I have a Vetus M41.7 diesel engine with twin alternators. The cable from the back of the alternator goes to the leisure battery isolator and then to a Victron Energy DC Link Box, from the same terminals cables go to the battery connections on the Vetus 1245 battery charger/splitter. There are no cables attached to the "alternator" connections on the charger/splitter, is this why the alternator is not charging the batteries and can I simply run cables from the DC link Box terminals to the alternator connections on the charger/splitter?

Tony-B
Tony-B

Posted: Sun Jul 24, 2016 8:00pm

Post Subject: No charge from alternator

I think the Vetus 1245 is a mains charger with the potential to charge 3 battery banks. It may or may not also split the charge from a single alternator so one alternator can charge up to 3 banks. have a look here http://www.vetus.com/electricity-on-board/batter y-chargers/vetus-combined-battery-charger-splitt er-12-v-45-a-for-3-battery-tanks.html#product_ta bs_technicalspecification_contents and see if you can get more sense out of the Vetus data for that machine. As you have not said that you have three battery banks I must assume that you only have two and in that case with twin alternators there is no need for alternator charge splitting. Each alternator charges just one bank with no extra complications. A sketch of the wiring emailed to Tony@tb-training.co.uk would help me make more sense of your words but I do not think the Link Box has anything to do with charging. I think it is just a junction box from which to take a number of feeds, possibly to the domestic equipment. Again with no information about which battery bank it is connected to this is only a guess. So from what I can glean this boils down to "my alternator has stopped charging" and nothing else. I think both alternators' outputs do run to their respective batteries, its just that you can not see where the connections are. Have you checked both alternator's drive belts are fitted, tight and in good condition? How many charge warning lamps do you have? Do they/it work? Is a relay used in one of the alternator's warning lamp circuits? How about sending a low res photo of the back of the alternators to Tony@tb-training.co.uk so I can see exactly how they are wired. There is also likely to be a large multi-plug hidden away somewhere in the main engine wiring harness. Try manipulating this to see if the fault clears. They are well know for developing dirty or loose connections. For no, to save getting flat batteries, when you start the engine pop a heavy jump lead between the engine and domestic battery bank positive terminals taking GREAT care not to allow a clip to touch any metal. Remove it whenever you stop the engine. This is a manual equivalence of a split charge relay and will allow the working alternator to charge both battery banks. I would also like to see the symptoms/readings of the fault that leads you to conclude one alternator is not charging. I assume that you have made sure all the alternator connections are tight and clean.

gsvmtv
gsvmtv

Posted: Tue Jul 26, 2016 5:19pm

Post Subject: No charge from alternator

Mant thanks Tony, will have another look and come back to you if needed. Cheers, Graham

gsvmtv
gsvmtv

Posted: Sun Jul 31, 2016 11:09am

Post Subject: No charge from alternator

Latest development which I don't know whether it is connected or not (excuse the pun!) is that yesterday I realised the shore power electricity card was down to zero having had £6 on it last week and usually using less than £1 per week. Tried to start the engine and the starter battery was completely flat, 0v on a meter! Jumped the battery from the leisure batteries and the glow plug lamp on the control panel stayed on and was still on after the engine had been cut. Does this mean the glowplugs have caused the starter battery to drain and will I need to replace them to solve the problem? Thanks..

Tony-B
Tony-B

Posted: Sun Jul 31, 2016 12:04pm

Post Subject: No charge from alternator

First of all I have still not seen the symptoms that made you conclude the alternator had failed. I am not 100% sure about the Vetus (things alter depending upon age and specification) but aglow plug warning lamp is not very usual on a boat so I wonder if the lamp is actually the charge warning lamp. That would make some sense re a faulty alternator. Are you sure the battery charger is connected to BOTH battery banks, the one you listed seems to have that capability but is it wired that way. Now the glowplugs. Faulty glowplugs are unlikely to cause the symptoms you describe. They are controlled via the ignition switch or a push button so if they have been on all the time something in the control circuit must have failed in the closed position. I think the Vetus uses a relay, usually mounted at the back of the cylinder head, and if the glowplugs really are on all the time I would suspect the relay has burned its contact together. However I feel the ongoing problems may indicate that a very methodical approach to fault finding is required, including the use of meters, to get find out exactly what it going on. With well charged engine batteries and the ignition turned on in the run position but not running put a voltmeter between any glowplug terminal and a clean metal part of the engine. Expected reading = zero. If it reads 12 volts go between the glowplug terminal on the back of the ignition switch and any negative. Expected reading = zero. 12V = faulty ignition switch. If it reads zero find the relay and pull it out and retest at the glowplugs. If the reading is now zero the relay is faulty.

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