gen251 Posted March 23, 2015 Share Posted March 23, 2015 Hi folks. Like most newbees I am seeking help! My auxiliary battery does not seem to be charging from the alternator whilst driving. The voltage at the battery is just over 9 volts. When plugged into mains at home the voltage is showing 13.6 - which I would expect. During habitation service a month ago they reported a sticking split charge relay which they said had been cleaned and then tested as OK. Can I replace the relay myself? Link to comment Share on other sites More sharing options...
lennyhb Posted March 23, 2015 Share Posted March 23, 2015 They are idiots sticking relays are not repairable, yes 5min job to change yourself. Link to comment Share on other sites More sharing options...
gen251 Posted March 23, 2015 Author Share Posted March 23, 2015 Hi Lenny Thanx for that. I did think it odd to 'clean up' a relay. Is the relay in the control box with the fuses and circuit breakers under the side seat - or does anyone else have details of what it would involve? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 24, 2015 Share Posted March 24, 2015 The motorhome’s alternator should be providing around 14 Volts to the leisure battery. The 9 Volts measurement with the vehicle’s motor running indicates two things 1: The battery is not receiving charge from the alternator. 2: The battery is very seriously discharged. (A battery with a measured Voltage of 12V or less should be considered ‘flat’.) Given the comment at the last habitation service, it seems reasonable to suspect that the split-charge relay is the culprit (I can’t advise where Elddis will have put the relay, though I’d begin looking for it close to the starter battery) but this may not be the case. This earlier discussion may be useful http://www.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Elddis-Leisure-Battery-Fuses/21370/ Whatever the cause of the problem, the leisure battery needs to be properly charged without delay using a charger able to cope with the battery’s heavily discharged condition. The motorhome’s mains-powered on-board charger may not be man enough for the task, but would be worth trying if there’s no easily available alternative. Link to comment Share on other sites More sharing options...
Rayjsj Posted March 24, 2015 Share Posted March 24, 2015 Saying that they 'cleaned the contacts' is either a lie, or they are stupid, as the relays are sealed, the act of trying to open one often destroys it. There are usually 2 relays together 1 for battery charging and one for running the fridge on 12v when the engine is running. Sometimes it is a single Heavy duty relay, with twin feeds but 2 is best practise.As stated usually under the bonnet but not always. A wiring diagram might help. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 24, 2015 Share Posted March 24, 2015 Gordon (gen251) actually wrote "During habitation service a month ago they reported a sticking split charge relay which they said had been cleaned and then tested as OK”. Nothing was said about repairing or dismantling the relay, nor of cleaning its contacts. I’m not exactly sure how one would diagnose a sticking split-charge relay, but cleaning the relay’s connectors MIGHT have been beneficial if Gordon had mentioned that there might be battery-charging problems. My first motorhome had its split-charge relay directly above its under-bonnet-located leisure battery. I had fitted the vehicle with a dashboard-mounted voltmeter (because I happened to have one) that could be used to individually monitor the charge being sent to the starter or leisure battery. On the day before travelling abroad I started the vehicle’s motor, switched the voltmeter to ’read’ the leisure battery’s voltage and found that it was still in the mid-12Vs. Cursing my luck (and more in hope than expectation) I wiggled the split-charge relay’s connectors and the voltmeter immediately gave a mid-14V reading that showed the alternator was now charging the leisure battery. I realised that, when I had been checking the leisure battery’s electrolyte level (a torch-and-mirror exercise) I had nudged a relay connector sufficiently to loosen it and stop it making a proper contact. A couple of cable-ties on the wiring to the relay made sure that the problem never recurred. Link to comment Share on other sites More sharing options...
Billggski Posted March 24, 2015 Share Posted March 24, 2015 Yes, the trouble with relays when they are playing up is that if you take them out and put them in again they can work. Until you are miles from anywhere in the dark. Link to comment Share on other sites More sharing options...
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