Scooter Posted November 7, 2011 Share Posted November 7, 2011 Just after some advice that may help me fix this quicker. The alternator/battery light and the rear light out and cat temp sensor lights are on when i first start the car and go off a short time after driving, and then come on again when I pull up to stop (idle) anywhere. I have searched and read this thread..... http://www.mkivsupra.net/vbb/showthread.php?221474-Can-alternator-fail-without-warning-lamp-coming-on/page2&highlight=alternator I've not had to jump start the car and when driving the (facelift) charge dial is showing over 12 volts. I have a spare alternator and i'm tempted to just pop it in but is it worth checking all the earths etc, it's just that if it was on permanently and it seemed the battery was being drained it's a no brainer but when it's intermitant and not seemingly causing any issues I just thought i'd ask. I'm going to whip off the fan belt at some point and check the alternator connections/earth too anything else to try? cheers Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted November 7, 2011 Share Posted November 7, 2011 Sounds like your alternator is buggered, you can try putting a volt meter on the battery when its running though to see whether its charging ok? Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 8, 2011 Author Share Posted November 8, 2011 can an alternator be part buggered? it's just i'd of thought it would kill the battery pretty quickly and i have done a fair few miles and startups to move it around the drive which i know is harder on the battery. Will get my meter and stuff out tomorrow and see what that tells me. Quote Link to comment Share on other sites More sharing options...
Scott Posted November 8, 2011 Share Posted November 8, 2011 Yeah when the alternator is on the way out it's current output will drop hence why you're getting the lights on at idle. When you are driving the speed of the alternator is increased which in turn increases its output, hence why it self corrects until it drops again. Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 8, 2011 Author Share Posted November 8, 2011 Well it's nice of it to die slowly Finally have a use for part of the whole spare engine that's been in the garage for years! Quote Link to comment Share on other sites More sharing options...
Scott Posted November 8, 2011 Share Posted November 8, 2011 Yeah sounds like it's just wear and tear rather than an all out self destruct. Quote Link to comment Share on other sites More sharing options...
SupraP-Z Posted November 9, 2011 Share Posted November 9, 2011 As above, most likely your alternator by the sounds of it, measure the voltage at the battery terminals on idle and tell us what its reading. I had a similar problem on a different car, the alternator would intermitantly charge the battery, sometimes wouldnt charge at all. I would get surges/loss of power, very dim to very bright lights etc...eventually it just stopped dead on me because the battery went flat lol. On mine it turned out to be a loose screw, best to check it out tbh. Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 13, 2011 Author Share Posted November 13, 2011 ok well, I removed the alternator I had on my spare engine, and this morning set about changing it. I should have carried out the volt tests etc but tbh it was all pointing towards a goosed alternator and as the mechanic sides of things is a bit of a hobby now I decided to get the experience of changing it regardless - that and it was a nice mild day for it! Bottom bolt was a little fiddly for access with the autofluid lines in close proximity but it went pretty smoothly and when fired up no more light. Cleared up and went out for a few miles with no problems, so thanks for the pointers. Quote Link to comment Share on other sites More sharing options...
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