fulani 4 Posted July 7, 2006 Car: Standard 1.9 GTI On the way home from the Nurburgring on Wednesday, I broke down about 10 miles south of Malmedy (near Spa-Francorchamps). Loads of backfiring and then the car cut out. A little jump start and charge got me about 3 miles, and a larger one almost to the Peugeot garage in Malmedy. I had to be towed the last mile. I suspected alternator failure, but as they didn't have any XU alternators in stock I bought a new battery (75!) which got me to Calais, and almost to the M25 on the way home. I bought a new alternator from Miles yesterday, and fitted it a la Haynes manual style, no slipping on the belt, all contacts cleaned, but now I've noticed the battery warning light on the dash is on. It's very feint (which may be why I didn't see it in the Belgian sunshine), but if I go over a bump it gets really bright. Does this light mean that the battery is not charging? I've put a multimeter over the battery, and it seems to be around 11.5 volts when switched off, 12v when switched on, and up to almost 15v when I give it some throttle. Sounds alright yeah? So why is the warning light coming on? Got back from Goodwood with no dramas (bar the light), but it did need a little coaxing to start. Help! Share this post Link to post Share on other sites
inferno 1 Posted July 7, 2006 (edited) sounds like some dodgy wires, the initial cutting out sounds like loss of spark, maybe the dizzy plug or coil. try checking wiring connections. the intermittent factor also suggests a dodgy plug partially connected, does the alternator charge light run through the brown multiplug over the gearbox? the battery should reach around 14.5volts on partial throttle, although i dont see that under 15v should be abnormal. also check the multiple earth terminals under the kickwell and on the inner wings for bad connections? Edited July 7, 2006 by inferno Share this post Link to post Share on other sites
pug309twin40s 1 Posted July 7, 2006 sounds like the new alternator is slightly duff. battery should be 12.4+v with engine off. 13+v with engine idling and about 14.5v with a few revs. you can put the meter on the alternator connections to see what its kicking out when running, incase theres any voltage dropping between alternator to battery. Share this post Link to post Share on other sites
Miles 331 1 Cars Posted July 7, 2006 It could be the main power lead running thru the starter motor getting to the battery, A Pain to get too but possible. Sound's odd that 2 alternator's didn't change the fault. Give me a buzz and we can get it sorted next week Share this post Link to post Share on other sites
M3Evo 0 Posted July 8, 2006 Hmmm, Stu's car had a pretty much exactly the same problem before it was taken off the road. Do we reckon an continuity check from the alternator to the battery +ve lead might shed any light? Guess you'd need to disconnect the battery first though. Share this post Link to post Share on other sites
jacobs53 0 Posted July 9, 2006 when the engine is off the battery should read 12.6V, when the engine is running at idle speed 13.8-9V, increased engine speed 14.0-14.3V... If when you start the car, the voltage increases the anywhere above 13.5V the alternator is charging fine. Sounds like a dodgy wire, maybe earthing out. cheers lee Share this post Link to post Share on other sites
t16ryan 1 Posted July 9, 2006 sounds like it could be a dodgy rectifier in the alternator, even though i think i spelt it wrong Share this post Link to post Share on other sites
fulani 4 Posted July 10, 2006 Just to make sure, I took off and cleaned all the contacts again, used a new nut and some WD40, and it seems to be running perfectly now. Stoopid thing. Share this post Link to post Share on other sites
Wurzel 16 Posted July 10, 2006 Just to add for any future search queries, the 'battery light' lead also acts as the excitation field to the alternator. I had lots of problems with charging and it turned out to be that small wire. After cleaning it up, finding out where it was shorting to earth (shorts create no battery light but also no excitation field and therefore a flat battery with no prior warning). A poor connection gives a very faint light, hardly noticeable in daylight but the battery will not charge. Glad to hear you got it sorted out now though. Share this post Link to post Share on other sites
richard 0 Posted July 10, 2006 Anyone got pics of this? Ive got a similar (dim light) problem and want to catch this in the bud, especially whilst im feeling handy, oooh er missus. Share this post Link to post Share on other sites
Cameron 16 Posted July 10, 2006 I had something just like this last year, it turned out that it was just some dirt caught under the battery wire where it attatches to the alt. cleaned it off and it worked fine. Share this post Link to post Share on other sites
