boxer1 Posted November 2, 2012 Share Posted November 2, 2012 I am unable to find the fuse between the alternator and the charger. The vehicle is an Autotrail Scout SE 2005. The leisure batteries were flat at the start of the journey and after 50 miles they were the same. They took the charge on electric ok. Could there be another reason for not charging when driving. Two new batteries were put in the vehicle approx 2 years ago. This summer they started to release gas. They were returned to the dealer who replaced them. Could this have something to do with it. The first two batteries which were maintenance free when opened were found to be dry?. Boxer1 Link to comment Share on other sites More sharing options...
Keithl Posted November 2, 2012 Share Posted November 2, 2012 Hi Boxer1, The first place to start looking would be next to the vehicle battery under the bonnet. You should find 2 or 3 fuses and 2 relays fairly close to the battery. Ours (on a Merc) are cable tied to the side of the heater intake duct. If you haven't got wiring diagrams you can download them from the Sargent Electrical website... Link Keith. Link to comment Share on other sites More sharing options...
Clive Posted November 4, 2012 Share Posted November 4, 2012 I agree. C. Link to comment Share on other sites More sharing options...
Tracker Posted November 4, 2012 Share Posted November 4, 2012 The fuses may well be intact when you do find them but the blades and contacts can get very dirty and corroded under the bonnet causing the continuity to fail. Try cleaning them up before looking elsewhere for problems. There may - or may not - also be fuses close to the batteries to which the same dirty theory applies? The best way to find out if you have charging from the alternator is by using a digital voltmeter to check the battery voltage with and without the engine running. Assuming the battery warning light on the dash goes out you will at least know that the alternator is chucking out a charge and checking the engine battery with the engine off and then running will confirm that. Link to comment Share on other sites More sharing options...
boxer1 Posted November 4, 2012 Author Share Posted November 4, 2012 Found the fuse and it is ok must be something else. Boxer1 Link to comment Share on other sites More sharing options...
Keithl Posted November 4, 2012 Share Posted November 4, 2012 Hi again Boxer1, Do you have a Digital Voltmeter, if not can you borrow or even buy one? This is an essential piece of kit for electrical fault finding! Starting at the engine battery measure the voltage across the terminals with the engine off then the engine on. You should see an increase from 12 point something volts to over 13 volts as the alternator charges the battery. Repeat this at the leisure battery. I will assume you see a rise at the engine battery but not the starter battery as this than confirms your leisure battery is not charging. Working from the engine battery positive terminal a RED wire will run to a pair of relays (changing to Brown at a junction), one is for leisure battery charging and the other to operate the fridge on 12v. To identify which is which start the engine, turn the fridge to 12v and check the warning light is on. Pull out one relay and see if the fridge goes off. If not repeat with the other relay. You now know which relay is for your split charge. It should have Brown and Brown/Blue wires. Do you have 12 v at both sides of the relay when the engine is running (Brown and Brown/Blue wires)? If yes move on and check the voltage either side of the fuse a few inches further up the wiring (Brown/Blue wire). Check this and report back and we'll advise further as the answers to these simple tests will help steer the direction for further tests. PS I've assumed that the fridge works OK when on 12v. Does it? Keith. Link to comment Share on other sites More sharing options...
Clive Posted November 5, 2012 Share Posted November 5, 2012 Could be a bad / corroded chassis connection for the split charge / fridge relays under the bonnet, not unusual. Or perhaps the rely is full of water. But YES get a multimeter and measure some volts in and out of the relay with the engine on fast tick over. The diagram on this link will give you a clue. http://www.motts.org/SPLIT%20CHARGING%20SYSTEM.htm Take care C. Link to comment Share on other sites More sharing options...
boxer1 Posted November 8, 2012 Author Share Posted November 8, 2012 The terminal was correded. Sprayed it, replaced the fuse and all working. Thanks to all for the advice. Boxer1 Link to comment Share on other sites More sharing options...
Tracker Posted November 8, 2012 Share Posted November 8, 2012 boxer1 - 2012-11-08 12:33 PM The terminal was corroded. Sprayed it, replaced the fuse and all working. Boxer1 Glad you sorted it but I suspect that spraying it alone will not prove to be a long term solution - but at least next time you discover an inconveniently flat battery after a long run you will know where to look! Link to comment Share on other sites More sharing options...
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