Led alternator light help.

[spanner1]

Hi people need some help I've built a dash assy for my mk1 and am using led warning lights, how do I get around alternator exciter wire as most of the current is used by led any help would be appreciated thanks.

[katana]

Sorry to say an LED won't work for this application! Normally when you turn the key on, power flows to the bulb and earths through the alternator to ground. With the engine running the alternator feeds power back the other way which cancels out the power from the key. Hence if the alt. gets weak, the reduced output allows the bulb to glow a little. The LED only allows electricals to flow one way and are pretty current sensitive and more than 2-300 milliamps will blow them to bits. I guess someone clever with electons could hook it up but its beyond my pay grade LOL!

[spanner1]

I have had a think today i wonder if this will work? any thoughts guys.

[Miniliteman]

Easy; use the std bulb but mount it somewhere behind the dash and wire the LED (with series resistor) parallel to the bulb.
Bulb will give the alternator the field-current it needs and as the LED is parallel to the bulb it will light up and go out same as the bulb.

[spanner1]

Thanks miniliteman thought there had to be an easy way around it, thats tomorrows job then...