Using LEDs for Turn Signals and Brake Lights..

Modulus · 05-19-2008, 11:19 AM

I just recently finished installing LED turn signals, front and rear, and LED brake light bulbs..

The turn signals (3-LED) are Watsens, they're great products from great people. The brake light bulbs (7443) are from Welcome to V-LEDS.COM.

I think most people are aware of the fact that replacing the stock turn signals with LEDs tends to result in a very fast blink-rate, or no blinking at all.

I don't think most people know why this happens, so I just wanted to briefly explain it, and give the cleanest fix that I've been able to find.

Normal incandescent light bulbs provide a much higher amount of resistance to the flow of electricity than that of LEDs. Replacing just the front or back turn signals with LEDs normally results in faster blink rate, about double. Replacing both the front and back can cause the signals to appear to run solidly.

The relay that causes the turn signals to flash, is a thermal relay. It is designed to operate at a certain amount of resistance, provided by the incandescent bulbs. Using LEDs drastically lowers the resistance in the circuit causing the thermal relay to operate out of 'spec.'

An electronic relay allows removes the resistance requirement from the blink-rate. The relay I'm currently using is from Custom LED. It's a simple plug and play installation. After disconnecting the stock thermal flasher relay, the Custom LED Electronic Relay connects to the stock harness. In the case of their programmable unit, different blink patterns are selectable.

Chum · 05-19-2008, 2:57 PM

Thanks. Very helpful.

curt248 · 05-19-2008, 3:02 PM

You sound just like me. I've been telling people this ever since I added leds to the front and rear blinkers of my bike.

Led's also light up much faster. You can see this when driving in stop and go traffic. Just look at the cars with led tailights (infinity g35's, nissan 350Z, etc.) and compare thier brake lights to cars without leds. The leds are instant while the incandscent bulbs are slow to light. It's a pretty cool thing to see.

Led's = safer (unless they are not bright enough of course)

Modulus · 05-20-2008, 2:56 PM

Yeah, I normally preach function over form, but I'll admit that it was a 90%/10% split in this case, still in favor of function..

It's definitely an HID, and the LEDs blink in a way that an incandescent bulb just isn't capable of.. They look pretty cool. But I wanted to see better (3200 lumen HID vs. ~1300 lumen Halogen), and be seen better with brighter/faster LEDs..

My car(TL) actually has LED turn signals on the mirror and incandescent bulbs in the front headlight housing, you can easily see how slow the bulbs light compared to the LEDs..