Harlan RPM switch - LED question
07-18-2004, 02:01 PM
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Harlan RPM switch - LED question I hope that I posted this in the correct forum. I have the Harlan RPM switch hooked up to my car as follows:
white wire -> relay
red wire -> + on battery
black wire -> grounded
green wire -> gets RPM signal from coil (using coil over plug setup)
The RPM switch itself has a LED on the circuit board. This LED is off on idle and at any RPM, upto the switch-over point. From then on, the LED is solid on.
I got a second LED from Radio Shack and I want to wire this one to my dash so that I can monitor the RPM switch's functionality. This LED comes with a red and black wire. However I am having some trouble getting this LED to work the same as the LED on the circuit board. When I connect the black to ground and the red to any of the other 3 coloured wires, it is always on (and in the green wire's case it flickers with the RPMs).
Can anyone help me out here? Hope I was descriptive enough in trying to explain what I want to accomplish here.
Thank you.
white wire -> relay
red wire -> + on battery
black wire -> grounded
green wire -> gets RPM signal from coil (using coil over plug setup)
The RPM switch itself has a LED on the circuit board. This LED is off on idle and at any RPM, upto the switch-over point. From then on, the LED is solid on.
I got a second LED from Radio Shack and I want to wire this one to my dash so that I can monitor the RPM switch's functionality. This LED comes with a red and black wire. However I am having some trouble getting this LED to work the same as the LED on the circuit board. When I connect the black to ground and the red to any of the other 3 coloured wires, it is always on (and in the green wire's case it flickers with the RPMs).
Can anyone help me out here? Hope I was descriptive enough in trying to explain what I want to accomplish here.
Thank you.
07-20-2004, 06:34 PM
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Okay I soldered a second LED (with a built-in resistor) to the same spot on the circuir board of the Harlan RPM switch and ran this LED to my dash. Works like a charm!
However the LED is very dim! I am afraid to get too powerful and LED because I am afraid of frying the board.
Can anyone give me any direction on what kind of an LED to get that will be brighter (at least more visible when it is bright and sunny outside) and at the same time not destroy the RPM switch itself? Right now, I am unable to tell when the LED comes on, when the sun is shining bright outside.
However the LED is very dim! I am afraid to get too powerful and LED because I am afraid of frying the board.
Can anyone give me any direction on what kind of an LED to get that will be brighter (at least more visible when it is bright and sunny outside) and at the same time not destroy the RPM switch itself? Right now, I am unable to tell when the LED comes on, when the sun is shining bright outside.
