battery or alternator?

Hi folks how r u? took the MG out for a spin today and after about 5 minutes driving the battery and ABS light came on, I got puzzled, after 1 minute the lights went off, then again after about another 3 minutes the battery light came on, then flickered and went off, arrived work, done my shift and left for home, this time the battery light came almost immediately on and stayed on, I also noticed that when I switch from dipped beam to high beam the radio went off and then on again! after a few minutes the battery light went off and the ABS light came on and stayed on after that, the steering light went on and then the SRS light came on, the dashlights dimmed and the car eventually stopped, when I tried starting it there was lots of ticking! I replaced the battery and the car started again but still the battery light flickered again and so did the ABS light if only just, can someone tell me what wrong please? thanks

Did you check the battery that you took off? If dead then its likely to be either the alternator OR the circuit of the alternator (maybe loose wiring) as it was not charging the battery. I must say all the lights on and off is a bit strange but then the ECU can do odd things when it's running out of power and the car is running. Especially if the alternator is giving power then not, then again,,

Someone more knowledgeable about these things will hopefully come along and give more advice but I'd start by having a look at alternator and the wiring.... also was the alternator belt slipping maybe? Any screeching noises?

Hi, thanks for the reply, no there weren't any screeching noises what I found odd is that usually when the alternator is to blame the batery light remains always on.

an again this mornin, decided to go for a spin to see iff anything happens as soon as I left I had the stereo on, and decided to put the lights on to see if anything happens, and yes the stereo went off an on again as soon a sI put the stereo on,this time no warning lamps came on but after about 10mins driving the stereo went off and didn't want to come on again so I put on the side of the road to see what happened, as soon as I braked the ABS light came on, I decided to switch the car off to see if when I restart the ABS lamp goes off but as soon as I tried to restart the car, nothing just the sound of a tired battery and lots of ticking, so I'm concluding alternator?? but if so why isn't the battery lamp constantly on? :S

Hi Frank,
do you have a multimeter to check the voltage at the battery?
Check the voltage across the battery terminals with everything off. Should be 12.0 - 12 .5 volts. If it's 11.0 - 12v, the battery's not charged fully. Any less and the battery is probably on the way out.
Start the car and check the voltage again. The voltage should now be over 13 volts, if not the alternator is faulty. Try turning on lights etc. If the voltage drops below 13v it confirms an alternator on the way out.

Thanks for that so I went to test it, the new battery I fitted was @ 12.84 before starting the car, when I started the car it went down to 12.17, the battery which was fitted to the car originally and which stopped working yesterday was @ 11.83 , so I fitted it to the car again and the car actually started!! when the car started the Volts went down to 11.17. so it looks as if something is draining the battery for a certain time but after some time the batteries regain thei energy??

FrankM83;14650 wrote: Thanks for that so I went to test it, the new battery I fitted was @ 12.84 before starting the car, when I started the car it went down to 12.17, the battery which was fitted to the car originally and which stopped working yesterday was @ 11.83 , so I fitted it to the car again and the car actually started!! when the car started the Volts went down to 11.17. so it looks as if something is draining the battery for a certain time but after some time the batteries regain thei energy??

Your alternator's had it, I'm afraid. It's not charging at all. Batteries will recover somewhat if left. But you should be getting something like 13.5- 13.8 volts with the engine running.

many thanks for that, will go and start removing it, wonder if it's a DIY job!

FrankM83;14655 wrote: many thanks for that, will go and start removing it, wonder if it's a DIY job!

Not too hard.:yesnod:
http://www.the-t-bar.com/showthread.php?59-How-to-change-the-alternator.&highlight=alternator