LED Turnsignals that won't light up

[FJmonkey]

Can a Bridge Rectifier work with DC input? I thought it was used to convert an alternating current (AC) to a polarized (DC like) current?

[jahearne]

The volt meter is reporting 6 volts while mounted on the bike. BTW, polarity now matters. I swapped the wires and sure enough they didn't work. With proper polarity, the inner lights works. Still no lights on the outer leds. I have yet to hook up the led mirrors directly to the battery while mounted.

[FJmonkey]

6 volts will be a problem. A typical LED will power with 5 Volts DC. To run them on a 12V system they add resistors to cut the voltage. So the 6 volts are going through the internal resistors to an even lower voltage. So one side tolerates the lower voltage and the other does not. Get the voltage back up to to 10+ and you should be good to go.  Your problem is low voltage at the mirror/LED signal assembly.

[fj-f3a]

Yes indeed, a Bridge Rectifier will work with DC Inputs.
Using a Bridge Rectifier on the supply allows the polarity to be connected either way and the device will still work.
Using a single diode on the supply will provide reverse polarity protection, but the polarity must be connected correctly for the device to work.

6 volts certainly is to low and I find this hard to believe. Definitely something wrong here.
Each individual LED requires between 1.8 and 2.2 volts to operate.
The usual maximum current for a typical 5mm LED is 20Ma.
There could be up to 7 LED's wired in series in each mirror and two lots of seven wired in parallel.
Maximum current would only be about 30 to 40Ma.        .

Did the standard blinkers work?
This will indicate if the blink unit was working and the contacts are in good condition.
A high resistance in the contacts would account for the low voltage.

Please connect direct to the battery again and report voltage.

If the Load Resistors are not installed, one would still expect to see the LED's illuminate but not blink.

[jahearne]

Thanks for the info! I'll get her hooked up to 12 direct. Currently I'm dealing with a carb leaking fuel, so soon as i get that dealt with...

[jahearne]

Have you tried the turn signals with the bike running? Current draw for the LED's should be less than an AMP. On the other hand, the LED's may need a solid 12volts or better to operate correctly.


Fred

You were right all along! I did get her running and even on choke the LED turnsignals weren't flashing. But during tune-up mode, I rev'd her up past 2,000 rpm and they lit up!!! They work once she was rev'd up. But nothing at idle. Which might be an issue at stop lights. However, could just be a bad battery, but she starts right up. Lights are bright. Anyways, I'll charge the battery overnight and hook up a voltmeter to the battery and while she's rev'd up to see where my voltage is at.

[jahearne]

Battery full charge! Same issue, the led turn signals light up when rev'd past 2,000 rpm.

[ryanschoebel]

Battery full charge! Same issue, the led turn signals light up when rev'd past 2,000 rpm.

What was the voltage? Could it be a bad alternator not producing enough voltage for them to light properly?

[jahearne]

Battery full charge! Same issue, the led turn signals light up when rev'd past 2,000 rpm.

What was the voltage? Could it be a bad alternator not producing enough voltage for them to light properly?

That was my first thought, but have yet to test it

[jahearne]

Sure enough, not producing 13-14 volts until it's rev'd up well past 2,000 rpm, more like 3000 to 3500. Nippon regulator on order!