Scott Posted October 29, 2008 Share Posted October 29, 2008 Hi there, Over the past couple of months i have been having trouble starting my car after a few days. It's not taking long to drain down at all. At first i thought it was the battery so i swopped it over with a yellow top. At first it was ok but now its dying after as little as a day. I thought it might have been my Amp's etc draining the battery, even though i wasn't turning off the stereo, so i disconnected the whole lot from the battery. Turned out it wasn't as nothing has changed. I ended up checking the terminals with a multimeter while the car was running and i'm only getting 12.7v. Could that be the problem? Not enough juice coming from the alternator to charge the battery properly? If so, does it mean a new alternator or is it possibly a bad earth or something? Any idea's what to check/replace first? I just don't want to go out buying more stuff i don't need. Thanks Quote Link to comment Share on other sites More sharing options...
absz Posted October 29, 2008 Share Posted October 29, 2008 engine running with with all lights and heaters turned on then 12.7 volts is fine but if every thing is switched off and engine running you should be seeing approx 13+ volts Quote Link to comment Share on other sites More sharing options...
Guest pitstopralph Posted October 29, 2008 Share Posted October 29, 2008 Ha.... I sent this to a mate of mine yesterday, Hope it helps. Get the battery drop tested mate, you’d be amazed at how many are faulty from new. Obviously you need to be happy that the Alternator is supplying not only enough volts but amps. If it’s ok, you need to measure the draw from the battery with everything turned off. You should get between nothing and an amp. [Depending on what security you have] More than an amp should be traced by removing each fuse in turn and watching to see which affects the draw. One you know which fuse it is you have narrowed down the user. Depending on what circuit it is you can then narrow it more by removing relevant relays or end users. I’ve seen most things, but the most common [after a boot or bonnet light staying on] is a door lock relay continually trying to lock an already locked door. Most decent Multimeters have amp clamps now, so this is something you could do at home. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 29, 2008 Author Share Posted October 29, 2008 My multimeter is crap though lol. Let me just check i'm remembering how to use this properly: For voltage i just check accross the terminals with everything on and with everything off to see the difference. For Ampage i check between the +ive terminal and positive cable, ie in series. Is that right? I remember doing all this sort of stuff in school but the fact that i'm told to use 0 gauge cabling for my amp would make me wonder about those tiny little multimeter leads lol. Thanks guys. Quote Link to comment Share on other sites More sharing options...
JustGav Posted October 29, 2008 Share Posted October 29, 2008 My multimeter is crap though lol. Let me just check i'm remembering how to use this properly: For voltage i just check accross the terminals with everything on and with everything off to see the difference. For Ampage i check between the +ive terminal and positive cable, ie in series. Is that right? I remember doing all this sort of stuff in school but the fact that i'm told to use 0 gauge cabling for my amp would make me wonder about those tiny little multimeter leads lol. Thanks guys. You will need a clamp ammeter... the normal ones are usually only rated to 10Amps... Quote Link to comment Share on other sites More sharing options...
Scott Posted October 29, 2008 Author Share Posted October 29, 2008 You will need a clamp ammeter... the normal ones are usually only rated to 10Amps... Yeah thats ringing a bit safer lol. Think it is 10 amps actually. Cheers Quote Link to comment Share on other sites More sharing options...
Scott Posted October 29, 2008 Author Share Posted October 29, 2008 Any info on where to get one? I checked maplins but it seems they only have ones that can check AC current. Quote Link to comment Share on other sites More sharing options...
JustGav Posted October 29, 2008 Share Posted October 29, 2008 Cheap and nasty... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260272129823&cguid=106e9e2e11d0a0e202967426fff69ce6 I just had a look and my fluke one is around £500, so that isn't really an option. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 29, 2008 Author Share Posted October 29, 2008 Cheap and nasty... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260272129823&cguid=106e9e2e11d0a0e202967426fff69ce6 I just had a look and my fluke one is around £500, so that isn't really an option. Can't get on ebay in work so will check later, cheers. Had a brief look around and saw one i reckon would suit my needs for around £50. I'll check the ebay ones though. Thanks Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted October 29, 2008 Share Posted October 29, 2008 This might sound really basic but i had this exact problem in one of my old cars. I noticed the stereo lights getting dim but just thought it was the bright sunlight, then i noticed when it was raining the wipers were really slow. Then it died on a petrol station forecourt so i changed the battery and all was well for about 3 or 4 days when it died aswell. I got under the car and had a good look around and found the cable from the alternator had fatigued and snapped and the only thing holding it on was a bit of insulation on the crimp and road grime. Would be worth a try looking if you haven't already. Quote Link to comment Share on other sites More sharing options...
Franko Posted October 29, 2008 Share Posted October 29, 2008 Scotster mate head up to Shandon Electrical in bellshill, they will tell you whats needed and they reburb alternators also if thats the fault. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 29, 2008 Author Share Posted October 29, 2008 This might sound really basic but i had this exact problem in one of my old cars. I noticed the stereo lights getting dim but just thought it was the bright sunlight, then i noticed when it was raining the wipers were really slow. Then it died on a petrol station forecourt so i changed the battery and all was well for about 3 or 4 days when it died aswell. I got under the car and had a good look around and found the cable from the alternator had fatigued and snapped and the only thing holding it on was a bit of insulation on the crimp and road grime. Would be worth a try looking if you haven't already. Will have a look at that Scotster mate head up to Shandon Electrical in bellshill, they will tell you whats needed and they reburb alternators also if thats the fault. Thanks mate, i'm going to have a tinker myself but if i hit a dead end and run out of hair to pull out i'll give them a go. Wasn't sure where to take it, you just don't know who to trust nowadays. Good to have a recommendation. Cheers guys Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2008 Author Share Posted November 4, 2008 Ok, clamp ammeter came today so i went out for a little check. With everything off it was coming up as 0.4amps. Is that a big drain? I had a little play with the wires at the alternator, i didn't pull anything out.. just gave them a wiggle. I then stuck the voltmeter accross the battery and now its reading 14.5 volts while running!! Wish i had done a before and after wiggle check now. I've fired it up and i'm letting it charge. Looks like it could be a dodgy connection at the alternator after all. If it doesn't hold a charge i'm taking it to the place Franko recommended. Cheers Scott Quote Link to comment Share on other sites More sharing options...
Guest pitstopralph Posted November 4, 2008 Share Posted November 4, 2008 That's about what I'd expect it to draw bud! Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2008 Author Share Posted November 4, 2008 That's about what I'd expect it to draw bud! Thanks. I'm just hoping its been a dodgy connection then. If i go out tomorrow and it fires up i think i may have found the culprite. Thing is, i didn't actually "find" it, i just wiggled about some wires lol. Would rather know what it was so i may still take it to a specialist. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
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