CURLY Posted August 12, 2009 Share Posted August 12, 2009 hi there, i have a 2.5 td 110 with dodgy wiring all over the place. my alternator isn't charging at all now, and even after changing it twice, it still doesn't charge. even though it was working fine 10 minutes before on the car i took it off.. it has 3 wires going to a triple spade connector plug, 2 big brown ones that go to B+ and a thin brown/yellow one that goes to the other smaller spade connector. but the new alternator has 3 bolts to plug the wires onto. B+ (2 x fat brown wires) W (nothing, cos its for the rev counter) and B+ (ignition warning lamp? or is it the alternator ignitor?) i read somewhere on here that if i unplug the brown/yellow wire from the back of the alternator it should read +12v with the ignition on. is this true? because if it is, then mine is wrong, because it is an earth with the ignition on?? the brown/yellow wire at the back of the ignition warning light is +12v too? and that brown/yellow wire to the light is connected to the ignition plug. what should it be? HELP!!!!! CURLY Quote Link to comment Share on other sites More sharing options...
ejparrott Posted August 12, 2009 Share Posted August 12, 2009 Im a bit confused by this one, I'll have to have a think... The ignition light works on the difference in voltage applied to each side of the bulb. It's fed 12v direct from the battery via the ignition switch, and if the engine is stopped the other side is 0v, therefore the light comes on. When the engine is started, you get 12v out of the alternator, putting 12v each side of the bulb, and therefore the light goes out... Any help? Quote Link to comment Share on other sites More sharing options...
western Posted August 12, 2009 Share Posted August 12, 2009 connect the 2 large brown wires onto one of the B+ [doesn't matter which one of the 2] the thin brown/yellow is the ignition/charge light needs to connect to the WL or IND terminal & W is for rev counter as you've stated. Quote Link to comment Share on other sites More sharing options...
CURLY Posted August 13, 2009 Author Share Posted August 13, 2009 connect the 2 large brown wires onto one of the B+ [doesn't matter which one of the 2] the thin brown/yellow is the ignition/charge light needs to connect to the WL or IND terminal & W is for rev counter as you've stated. Ok, done that, but it's still not charging! I can't beleive that all 3 alternators would be buggered surely? Is the brown/yellow wire supposed to be +12v with the ignition on, or -12v? Cheers, CURLY Quote Link to comment Share on other sites More sharing options...
CURLY Posted August 13, 2009 Author Share Posted August 13, 2009 Ok, done that, but it's still not charging! I can't beleive that all 3 alternators would be buggered surely? Is the brown/yellow wire supposed to be +12v with the ignition on, or -12v? Cheers, CURLY where is the charge light resistor, and what does it look like, how can I tell if it's working? CURLY Quote Link to comment Share on other sites More sharing options...
western Posted August 13, 2009 Share Posted August 13, 2009 where is the charge light resistor, and what does it look like, how can I tell if it's working? CURLY charge light resistor is within the main dash area wiring loom, bit of a job to pull it all out to find the resistor. charge light brown/yellow wire should have 12v +ve with the ignition switched on so the light is illuminated Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted August 13, 2009 Share Posted August 13, 2009 It's the current flowing through the Warning light that is used by the alternator to excite the field winding before the alternator has spun up and is working. Once the alternator is working, the regulator takes over control of the field winding, and the WL wire ends up with battery voltage on it - hence the warning light going out - it has the same ~14v on both sides of it. Quote Link to comment Share on other sites More sharing options...
CURLY Posted August 13, 2009 Author Share Posted August 13, 2009 charge light resistor is within the main dash area wiring loom, bit of a job to pull it all out to find the resistor. charge light brown/yellow wire should have 12v +ve with the ignition switched on so the light is illuminated do you know what the resistor looks like? Is it a 25-30mm long black thing with a triangle on it with a male spade one end, and a female the other? I have got 2 of those behind the dash clocks, can't remember what wires they are on though, I'll have a look if that's what it is. The sign on it looks a bit like this if I remember correctly. ->- all in a circle. It's started to charge again now, but only at 13.8v. But my battery which is a pc1700 super duper one has a cyclic charge that only works between 14.2 and 14.5 volts and it has a slow charge from 13 to 13.8 volts, so it's not going to charge properly is it? Oh man, what do I do? Quote Link to comment Share on other sites More sharing options...
western Posted August 13, 2009 Share Posted August 13, 2009 IIRC those are diodes to do with the voltage sensitive switch [big yellow type relay in far right corner behind the small 3 rocker switch panel] the resistor is referred to in this thread http://forums.lr4x4.com/index.php?showtopic=45294&view=&hl=charge Quote Link to comment Share on other sites More sharing options...
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