Good evening all I have had a look for a thread related to this issue but can't find anything,so here goes. I am coming to the end of my defender 90 300tdi build,when starting,the ignition light comes on (battery light) but does not go out when started. If I bridge b+ and d+ it charges at 14.5v and the battery light goes out,likewise, if I put a feed to the warning light when the engine is running the same also happens. There is two brown/yellow wires at the dash,I'm guessing one goes to the alternator and i think the other goes to a white wire with inline resistor. Does anyone have any ideas please? I will be very grateful. Thanks, Matt
Defender 300tdi battery warning light
- Thread starter Matty p
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Sorry no pics I'm afraid.
Hopefully someone will have an idea, im just about at my wits end!No worries, all fixable when the good guys arrive.
J
mystery
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discool
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So your vehicles battery isn’t charging then ? then an iffy alternator regulator pack is a possibility.Hopefully someone will have an idea, im just about at my wits end!
Wiring diagrams won’t tell u that but testing will
v8250
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@Matty p , this may help you to understand alternator ccts a little more...they're very simple to fault find and fix https://www.howacarworks.com/ignition-system/troubleshooting-the-ignition-warning-light
Hi all and thanks for your help,much appreciated. I am writing this from the front seat of my 90 still trying to work out what feeds the brown/yellow at the bulb to put it out when running and also excite the alternator? If i put my power probe at brown/yellow and give it 12v when running, the light goes out and charges normally. Im almost bald already but this will finish it off i think!!!
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B+ is normally the battery positive, sometimes you'll see D+ as the battery positive, depending on the make. Never seen both on the same unit before
W is usually for the engine RPM signal. If that helps
W is usually for the engine RPM signal. If that helps
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Alternator Terminals Explained - Conquerall Electrical Ltd
Alternator Terminals Explained-If you've ever wondered what all the connections on your alternator do, you've come to the right place. In this article,
conquerallelectrical.ca
The B+ terminal is the actual high-current output, and the D+ terminal is a duplicate of the B+ terminal. The D+ diodes have lower current ratings. The B+ and D+ terminals are connected through the same set of windings on the alternator.
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Ok, so B+ to the battery, charge warning to D+...
You say the light comes on, do get 12v to the wire that connects to D+ with the ignition on? Is there a good earth?
So with the d+ wire disconnected from the alternator,there is 12v at the terminal. Once the terminal is back on the alternator and engine running it measures approximately 2v,obviously not enough to excite the field coils. It seems like a poor connection maybe? I just cant find where the 12v comes from.
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I think it's a thin brown wire, should be pretty obvious
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Sorry. It should be a switched live off the ignition. I don't have the details for your motor.
When you bridged the B and D, did the ignition light go out? I assume not? If the signal wire isn't getting 12v but the day light is on then I'd be looking at whatever is behind the dash.. possibly a diode problem
When you bridged the B and D, did the ignition light go out? I assume not? If the signal wire isn't getting 12v but the day light is on then I'd be looking at whatever is behind the dash.. possibly a diode problem
