Alberta Land Rover Enthusiasts Club Forum
General => Technical Discussions => Topic started by: northerndefender on April 15, 2017, 07:13 PM
I am wiring up my new alternator and need to know how large the current is that is fed on the D+ connector.
The alternator is a lucas type A127.
The current is usually limited by the warning light bulb that comes from the ignition. Since I am using LEDs instead of an incandescent bulb I need a resistor instead hence I need to know the current.
100 Ohms at 2W seems to be bantered around on the net but I would appreciate a current spec if any one has it.
I fired up the rover for the first time in 8 months and it sounded great ;D
Cheers
Colin
Are you not using a 12V LED? If not the resistor is set to get the voltage and amperage that is set by the LED specs.
Keep in mind there may already be a diode in the line depending on the year. That will cause a voltage drop which will affect the LED.
The led on its own will not provide enough current to activate the regulator so a parallel resistor is used. This is a popular circuit but I think there is an implied current limiting resistor in the LED...
The issue came about because the reproduction lenses I am using are not rated for the heat put out by an indandescent bulb.
There is already a resistor in parallel with the stock bulb. Current through the light is not required.
Oh hang on. What type of vehicle are we talking about?
I guess it is a series by the picture....
The stock resistor in a Defender is 100 Ohm, 5 W.
Resistor and a bulb ! I will have to do some more digging.