Mikey Posted October 11, 2007 Share Posted October 11, 2007 The other morning my 300Tdi auto wouldn't start. The battery was very low, just enough to heat the glow plugs but not enough to turn over the engine. So I walked to work. When I got home the battery was totally flat, not even enough power to light up the dash lights. I had no previous warning of the battery getting low, vehicle was fine the day before. I didn't have time to investigate possible causes so I bought a new battery. Anyway today whilst under the bonnet I noticed a quiet but high pitched whistling type noise. (ignition was turned off). The noise seemed to come from the general area of the alternator, but not certain. I am concerned that something may be constantly draining the battery. Can anyone throw any light onto a "possible" problem. Further info: The vehicle is fitted with a non standard CD player, and a non standard imobilisor and alarm, also Range Rover electrical seats. I assume that all these are wired corretly. The vehicle had an MOT over the weekend, don't suppose they would have disturbed anything electrical? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 11, 2007 Share Posted October 11, 2007 Sounds like the alt could have a dead regulator. To track down a current drain, remove one of the battery leads (-ve is safer) and put an ammeter between it and the battery terminal. Then disconnect things (or pull fuses) until the current draw drops to "not much". I'd start by disconnecting the alternator charge wire to see what happens. You should have less than 1 amp draw, give or take dependent on alarms, interior lights, stereo memory, etc. Quote Link to comment Share on other sites More sharing options...
66gaza Posted October 11, 2007 Share Posted October 11, 2007 The other morning my 300Tdi auto wouldn't start. The battery was very low, just enough to heat the glow plugs but not enough to turn over the engine. So I walked to work. When I got home the battery was totally flat, not even enough power to light up the dash lights. I had no previous warning of the battery getting low, vehicle was fine the day before.I didn't have time to investigate possible causes so I bought a new battery. Anyway today whilst under the bonnet I noticed a quiet but high pitched whistling type noise. (ignition was turned off). The noise seemed to come from the general area of the alternator, but not certain. I am concerned that something may be constantly draining the battery. Can anyone throw any light onto a "possible" problem. Further info: The vehicle is fitted with a non standard CD player, and a non standard imobilisor and alarm, also Range Rover electrical seats. I assume that all these are wired corretly. The vehicle had an MOT over the weekend, don't suppose they would have disturbed anything electrical? I have a similar noise that comes from my alternator but only when the ignition is on, if I turn the ignition off the noise stops and it is definitely from the alternator. Not sure what your fault is but I don't think it should be doing it when the ignition is off. Sorry I can't be of more help. Gaza Quote Link to comment Share on other sites More sharing options...
BogMonster Posted October 11, 2007 Share Posted October 11, 2007 Much less than 1 amp IMHO - if its over 100 milliamps it will flatten a battery over a period of a few days. I agree though - regulator sounds like a strong culprit Quote Link to comment Share on other sites More sharing options...
Mikey Posted October 11, 2007 Author Share Posted October 11, 2007 OK, the alternator is still making the noise when the ignitions is turned off. Forgot to say that the warning light does not come on at all when ignition turned on. I will try to get it seen in the morning by an auto electrician. Another question, is the regulator complete with the alternator or a seperate part? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 11, 2007 Share Posted October 11, 2007 Another question, is the regulator complete with the alternator or a seperate part? Without seeing it I can't be 100% but many are - Lucas and Bosch often are. Why pay an auto electrician? This could involve two screws and a connector... I think the regulator packs are ~£12 new. Quote Link to comment Share on other sites More sharing options...
Mikey Posted October 12, 2007 Author Share Posted October 12, 2007 I have just checked, I have a Magneti Marelli A1271 - 100Amp fitted. Been informed that no spares are available other than brushes and bearings. Replacement is aprox £160. A company on internet has alternative model availlable for aprox £65 made by torq x or similar name. My dilemma right now. Existing alternator is actually charging when running, but makes a strange buzzing/whistling noise when not running, and is probably discharging the battery slowly. So do I do nothing and cross my fingers. Or do I buy a new item or maybe even a cheap alternative? I don't have too much to spend at the moment. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 12, 2007 Share Posted October 12, 2007 Or you could hunt round eBay / scrapyard for a replacement - as long as it mounts the same way and has a similar pulley you can fit pretty much any alternator. A mondeo alt will be cheap and kicks out 90A. Quote Link to comment Share on other sites More sharing options...
Mikey Posted October 12, 2007 Author Share Posted October 12, 2007 Or you could hunt round eBay / scrapyard for a replacement - as long as it mounts the same way and has a similar pulley you can fit pretty much any alternator. A mondeo alt will be cheap and kicks out 90A. I guess I was coming around to that I idea, cheers. Quote Link to comment Share on other sites More sharing options...
Guy H Posted October 12, 2007 Share Posted October 12, 2007 Or try http://www.lro.com/forum/viewtopic.php?p=33131 on the LRO forum he's breaking a 300tdi engine. Quote Link to comment Share on other sites More sharing options...
Guy H Posted October 12, 2007 Share Posted October 12, 2007 or http://contact.ebay.co.uk/ws1/eBayISAPI.dl...em=110178999672 Quote Link to comment Share on other sites More sharing options...
Mikey Posted October 13, 2007 Author Share Posted October 13, 2007 Thanks for that Guy. A mate of mine down south has got a garage, he is trying to track me down a decent alternator. Thanks again. Quote Link to comment Share on other sites More sharing options...
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