GLPoomobile 958 Posted April 5, 2006 Drove home the other day with sidelights and heater on full whack the whole time for just over an hour. The last 30 minutes through London was slow so spent a lot of time idling or just crawling along. Anyway, when I got home I wanted to do a quick test on the immobiliser due to an embarassing incident at traffic lights 5 minutes before. Switched off for 30 seconds, let the immob come on, then deactivated it and started the car (without lights, blower or any other drain on the system). It started immediately but the starter sounded a tiny bit weaker and it was idling lower. Gave it a few blips and ran it for 30 seconds. Turned off and tried to start it again. This time the starter was much weaker and would not start, and after a few seconds it was clear that the battery was dying. I haven't noticed the warning light come on during driving and wasn't focussing on it at the time that this happended. I do have a known good alternator and battery that I can swap over but I'm just curious as to which is likely to be the cause. Share this post Link to post Share on other sites
Jonmurgie 2 Posted April 5, 2006 Sounds like it's probably a dead battery not holding charge to me... if you change one thing at a time then you will know what it is, so stick in the decent battery first and see how that goes Share this post Link to post Share on other sites
jackherer 543 Posted April 5, 2006 does the battery light come on when the ignition is on and the engine not running as it should? Share this post Link to post Share on other sites
GLPoomobile 958 Posted April 5, 2006 Sounds like it's probably a dead battery not holding charge to me... if you change one thing at a time then you will know what it is, so stick in the decent battery first and see how that goes Yeah, but living in London it's not wise to drive a car anywhere if you are at risk of breaking down cos you'll inevitably get a ticket within minutes! I'm just goint to swap the battery and alternator anyway. Just thought I'd ask out of interest. Share this post Link to post Share on other sites
GLPoomobile 958 Posted April 9, 2006 (edited) OK, so I'm really confused now. I left the car for a couple of days and went out thursday night to see if the battery had somehow regained any charge. It started first time and idled fine. Ran it at fast idle for about 15 minutes hoping to get some charge into it. On friday morning I decided to risk it and drive to work. Fine all the way there. Driving home it was fine until I got into London traffic. First of all I noticed it was running a bit rough, and it slowly got worse to the point it felt like it wasn't firing on all cylinders. The idle had also started to drop down to about 600rpm so I realised it must be the alternator/battery. Start s*itting myself thinking I'm going to break down! At the traffic lights next to my flat the inidcators are working really slowly. I manage to pull into my street and park up. Turn the car off and then try to restart it and there is virtually nothing left of the battery again. Yesterday I went out and tried it again, and although not 100% strong, it did start and run. What's going on? If either the battery or alternator are faulty, how did it regain and hold enough charge to get the 45 miles to work and back before losing charge again? I will be swapping the battery and alternator as I said earlier, I just don't get the logic behind this! Edited April 9, 2006 by GLPoomobile Share this post Link to post Share on other sites
huxley309 0 Posted April 9, 2006 Voltage regulator on the alternator on its way...commmon fault ive had 3 of the things go this way When running switch on as much electricals as you can...if she dies thats your problem most of the time people think dead battery Share this post Link to post Share on other sites
petert 587 Posted April 9, 2006 Stick a voltmeter on the battery while it's idling (fast). If its not between 13.8 and 14.4V you have an alternator problem. Share this post Link to post Share on other sites
