The resistors are there to limit the current running thru the diode, not for dimming.I have a set for an early X1/9. Sorry I can't tell you what size they are, other than they're tiny, or where you can get them. They are easy to construct all you need is a hot glue gun. Mine each have a small resistor installed to keep the brightness down. They work great, but now they have two wires to each, not just one fiber optic cable.
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Doesn't that dim them?The resistors are there to limit the current running thru the diode, not for dimming.
Those look like what I have. They should work very well for you. And cheap too! And shipping from Georgia, no waiting 4wks to receive them.Thanks Mike, I was thinking of hot glue too.
Based on Dan's suggestion I ordered the following.
https://www.ebay.com/itm/1-8mm-2mm-...D-DC9-12V-Lights-Emitting-Diodes/382850844974
3mm Pre Wired LED DC9-12V Lights
The LEDs with resistors commonly sold have the resistor in series with the LED to limit the maximum current. If you connected an LED directly to a 12V battery, you would get a little puff of smoke and that would be the end of it. If you have a resistor in series with the LED so that it runs at a reasonable current, it is likely to last forever. These LEDs draw much less current than the incandescent bulbs they replace and their radiation patterns can be optimized better for certain applications which can make them even more efficient. Putting the resistor in series with the LED will not cause the device to draw more current. The same current going through the LED is going through the resistor, and the larger the resistor, the lower the current will be. You may be thinking of the resistors put in parallel with LEDs so they draw enough current to make a flasher work or for the car electronics to think there is a bulb there. The festoon bulb I recently bought for the overhead light had some electronics built into it that will supposedly let a CANBUS know it is there. It also makes it polarity insensitive so I am guessing there is a bridge rectifier in series with it as well.This has confused me a little. All of the LED's I've purchased were advertised for 12V and required no additional resistors. And many of them are listed as working for a rather wide range of voltages, also without adding resistors. I thought the main reason a resistor was added to any LED's was to prevent false error codes on more modern cars that sense bulb draw to tell you when one is burned out, or to make the incorrect type flasher work with them? Otherwise adding any resistance to a LED seems to negate one it it's biggest benefits - less draw on our very borderline electrical systems. As for dimming a bright LED, wouldn't it better to use an appropriate dimmer? Like the later type electronic rheostat that Karl mentoned? That also makes it adjustable brightness. As for "protecting" the diode, I thought that was another one of their big benefits - they last forever. So why would you need to protect it? All of the numerous LED's I've used have lasted for years without adding any resistors. Perhaps I'm missing the point of this resistor topic?