plawson63 Posted September 13, 2008 Share Posted September 13, 2008 hey guys,the charge warning lamp came on today while i was driving about,i looked in the book and i have tightened the drive belt to what it says in the book. Then i turned the car on for 3 mins and the light didnt disappear,whats the next stage????i could tighten it more. The car still starts ok. Pete Quote Link to comment Share on other sites More sharing options...
Bob Green Posted September 13, 2008 Share Posted September 13, 2008 If the belt is at the recommened tension, there is no point in adding extra tension. Do a voltage test on the Alternator across the "+" terminal with the engine at 2.000 rpm. You are looking for at least 14.4 volts. That will tell you the output of the Alternator. Any less, it's died. Quote Link to comment Share on other sites More sharing options...
plawson63 Posted September 13, 2008 Author Share Posted September 13, 2008 ok mate,i ll borrow a mates voltage tester,where abouts is the + terminal??newbie,ha. Car is only a 57reg Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted September 13, 2008 Share Posted September 13, 2008 You can check the battery volts across the terminals its the same thing 14.7 volts with the engine running Before you do anything though check the leads to the alternator havn't just worked loose Quote Link to comment Share on other sites More sharing options...
Hammy Posted September 13, 2008 Share Posted September 13, 2008 If you've no voltmeter -leave the headlamps on for five minutes then start and rev up - if they don't get any brighter you are not charging Quote Link to comment Share on other sites More sharing options...
Blatman Posted September 14, 2008 Share Posted September 14, 2008 Alternator testing... With the engine off and keys out, measure across the two battery terminals. 12.6 volts is a fully chatged battery. 12.3 volts or less and it's down by as much as 50%. Now, start the engine and let it settle to warm/hot idle. Measure across the battery again. Anything less than about 13 - 13.5 volts suggests a duff alternator. Rev to 2000rpm and hold. Measure again. Anything less than 14 volts suggests a duff alternator. Now, at tickover switch all the lights on, as well as the heater and anything else that works with electricity. Measure. Less than 12 volts suggests a duff alternator. Up to 2000rpm again and anything less than 14 volts suggests a duff alternator. Final test. With the multimeter attached to the battery, get a friend to switch all the lights etc off. If the power spikes up above 15 volts, it's a duff alternator. Be careful because you run the risk of frying the ECU (if fitted) because uncontrolled power spikes are bad. A properly working alternator should be showing 14.4 volts across the battery at around 1500 - 2000 rpm, and should not let power spike or dip beyond the 12 volt to 14.5/15 volt range. Quote Link to comment Share on other sites More sharing options...
Andrew Beattie Posted September 15, 2008 Share Posted September 15, 2008 Also dont forget to check fuses in the charging circuit as I did a while ago on my spliced in toyota loom... now I have two fully functioning alternators! Quote Link to comment Share on other sites More sharing options...
Kevin Wood Posted September 15, 2008 Share Posted September 15, 2008 It's also worth checking that the case of the alternator is grounding to the engine block and the engine block is strapped to the battery negative terminal / chassis ground point. The alternator relies on its' mountings for the negative connection and these can corrode or work loose. I have added an additional earth strap between alternator body and engine just to be on the safe side. An easy check is to run the engine and check the voltage between the alternator case and the battery negative terminal. It should be a few tenths of a volt at the most. Having said that, if the charge warning light is on, a faulty alternator is the most likely explanation IMHO. Kevin Quote Link to comment Share on other sites More sharing options...
plawson63 Posted September 15, 2008 Author Share Posted September 15, 2008 just had the lights on for 5 mins and tried to start it,it wont start,so i gather its knackered??how much is a new one?? Pete Quote Link to comment Share on other sites More sharing options...
jak Posted September 15, 2008 Share Posted September 15, 2008 Before potentially wasting money, get a multimeter and test it properly after charging the battery. Quote Link to comment Share on other sites More sharing options...
Blatman Posted September 15, 2008 Share Posted September 15, 2008 Sometimes I wonder why I bother Quote Link to comment Share on other sites More sharing options...
jak Posted September 15, 2008 Share Posted September 15, 2008 Sometimes I wonder why I bother Why did you offer some advice. Quote Link to comment Share on other sites More sharing options...
Blatman Posted September 15, 2008 Share Posted September 15, 2008 No, not reailly... Quote Link to comment Share on other sites More sharing options...
samcooke Posted September 15, 2008 Share Posted September 15, 2008 plawson63 is a veteran of 35 posts, meaning he's had plenty of time to find the button for Blatman. Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted September 15, 2008 Share Posted September 15, 2008 quote blatters QUOTE With the engine off and keys out, measure across the two battery terminals. 12.6 volts is a fully chatged battery. 12.3 volts or less and it's down by as much as 50%. He is probably still looking for the "chatged" battery Quote Link to comment Share on other sites More sharing options...
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