Jrod 7 Posted February 4, 2007 Well I've just fitted the engine from my old car into Sams shell. When you turn the ignition light on the battery light didn't light up but only glows, when I started the engine it didn't get any brighter or dimmer. Well I drove to Sams today to drop off a gearbox, went to start it and nothing so obviously It wasn't being charged. Bumped it and managed to get home with a lot of spluttering. So I changed the alternator, battery and made sure all the plugs were secure and now when I turn the ignition light on th battery light comes on bright like it should. If I then start the car the battery light practically goes out but not completly, giving it some revs doesn't make any real difference. If the batttery light is only slightly glowing does it mean the battery is not getting enough charge? I will have a check with a multimeter thingy tomorrow but just wondered if anyone had any ideas as to what could cause it if it's not the alternator. Share this post Link to post Share on other sites
brianthemagical 1 Posted February 4, 2007 not entirly sure but i'm guessing it's like a voltage light. to me it would indicate the alternator regulator is knackered or theres a wiring fault somewhere. see what happens with your mm. Share this post Link to post Share on other sites
Jrod 7 Posted February 5, 2007 (edited) So I got the multimeter on it today. I wasnt sure exactly what to measure in but I used DCV 20 Reading with engine off was about 17 and when running 20. When reved though it would jump up to 50 odd I'm guessing this isnt normal, any ideas what could be causing it beaing in mind I just replaced the alternator Does the little wire on the starter motor have anything to do with charging etc? Edited February 5, 2007 by Jrod Share this post Link to post Share on other sites
Jrod 7 Posted February 5, 2007 Right had a look and now its making around 14-15 with engine off (god only knows what I was doing earlier!) and it doesnt increase when running, if anything it drops a little. There is 1 main wire coming off the alternator going to the starter motor and from there to the + on the battery, that is right yes? There is also a little plug which when unplugged the battery light doesnt come on at all. On sams alternator there is a black wire coming off the alternator but i dont know where this went and mine doesnt have it?! How can I test the alternator on its own as im thinking maybe the wiring from there to the battery is faulty. Share this post Link to post Share on other sites
Anthony 1,003 Posted February 5, 2007 There's something wrong there with your meter I'd say, as there's no way you're going to be seeing 14-15v without the engine running. You should be seeing around 12.5-12.7v with the engine off and a healthy charged battery, and around 13-14.5v with the engine running (should be 14v+ with a healthy alternator and low electrical load) Share this post Link to post Share on other sites
Jrod 7 Posted February 5, 2007 It might be something to do with I don't know how to use it! Well either way I think I've fixed it... I took the wire going from alternator to starter off and replaced it with a spare. Put a flat battery in and started it with some jump leads, after running it for a bit the battery now starts the car which means it is now being charged! Not sure if it's getting as much charge as it should but I will try and get a friend to test it. Share this post Link to post Share on other sites
brianthemagical 1 Posted February 5, 2007 How can I test the alternator on its own as im thinking maybe the wiring from there to the battery is faulty. disconect all the wires from the alterntor, be carful as i almost set my car on fire last time a touched an alternator. it helps if your got another car jumping at the same time but you don't need one, just start the car with all electrical loads off and put a meter across the alternator and see what it says. Share this post Link to post Share on other sites
Jrod 7 Posted February 5, 2007 It's fixed now. Was a dodgy wire between the alternator and battery. 12.5 with engine off and 14 with it on. Share this post Link to post Share on other sites
