Need Help Fitting LED indicators in parallel with OEM incandescent indicators

[Neil_S999]

NC750S 67 plate.
I have a Givi Top Box and have fitted a pair of LED indicators to it as I wanted high level ones that motorists would see and to also complement the pair of combined rear/brake LED lights which work a treat and increase my visibility. I have tapped into the OEM rear indicators circuit and routed the 4 wires up to the top box (2 live 2 ground). Connected them up and activated the L/H indicator. Lo and behold the L/H LED flashed in sequence with the OEM L/H indicator. So I thought great, just what I wanted. My euphoria was dampened when I activated the R/H indicator as only the OEM one worked. Checked the wiring with a test lamp at the point where the new wiring connected to the LED wires. All OK, the test lamp flashed in sequence with the OEM one. My obvious thought was that the R/H LED is defective. I connected a power supply directly to the R/H LED wires. The R/H LED was not defective. I have ordered a replacement LED compatible indicator relay which has yet to arrive. Any advice would be appreciated as to how I can remedy this.

 

[670cc]

I don’t know the type of test lamp you used or how much voltage and current it requires to light it. The only defect I can imagine here is that there is a resistive connection somewhere in the wiring feeding the R/H LED. The resistance is such that the test light will illuminate, but there is too much voltage drop over the resistive connection for the R/H LED signal to light. If this were my project, I’d use a voltmeter to measure the voltage at the input to the LED when you activate the right signal. I don’t bother with test lights as they provide insufficient information.

You said you connected a power supply directly to the R/H LED and it lit, so I assume the LED polarity is correct in your installation.

 

[Neil_S999]

Thanks for your reply. Just a cheapo test light. Like a screwdriver with a light in the handle. Will borrow my neighbors multimeter. Checked the polarity. AOK. LED has 2 wires. One red (live) one white (neg). As I said, I have ordered an LED compatible flasher relay mainly because resistors build up too much heat. Do you think the relay may sort the problem? BTW I am in the UK. My model is a 750s which is a naked bike and sits lower than the X model. Where are you in the US?

 

[670cc]

Thanks for your reply. Just a cheapo test light. Like a screwdriver with a light in the handle. Will borrow my neighbors multimeter. Checked the polarity. AOK. LED has 2 wires. One red (live) one white (neg). As I said, I have ordered an LED compatible flasher relay mainly because resistors build up too much heat. Do you think the relay may sort the problem? BTW I am in the UK. My model is a 750s which is a naked bike and sits lower than the X model. Where are you in the US?

If the present turn signal flasher works for the left side, it should work for the right side, since the electrical load is the same. I assume your front signal bulbs are good.