LED Conversion - Lights Stopped Working

[westonjezek]

Hi All.

New to BMW motorcycles, so thought I should reach out with a wiring question on my 1995 R100RT

The Problem: I swapped out my stock headlight for a turn signal integrated LED headlight. Plugged everything back in the way it came out and capped-off the ground wires since the new headlight provides a common ground. (still waiting on a LED flasher relay to arrive)

The symptoms: Now horn, tail light, brake light, and all turn signals will not work unless the high beam flasher is engaged.

here is a video to show you the issue: https://coxautoinc-my.sharepoint.com/:v ... Q?e=mKCm3M

Any ideas?

[jagarra]

I have heard from other forums is that led conversions sometimes have issues because they don't draw enough current, for turn signal flashers to work. Reducing grounds is also bad, I would keep separate ground wires from lights and not rely on a path through a fixture.

[Rob Frankham]

Sorry, get a blank screen from that link...

What model and year is the bike?

Rob

[westonjezek]

Sorry, get a blank screen from that link...

What model and year is the bike?

Rob

Hey Rob, just give the video at that link a second to load and you should be able to play.

The bike is a 1995 R100 RT.

[Rob Frankham]

Trying to figure it out logically and not getting very far... not helped by the fact that the area around the dip switch on the Haynes diagram for that model is a complete work of fiction..

Is the headlamp working as expected... i.e. main beam when the switch is on main beam and dip when it is on dip?

In the meantime, please check the fuses... I don't think it is the only issue but, if the fuse with the green and green/black wires is blow or missing, it would go some way towards explaining why the horn, indicators and brake lamp are affected by the headlamp flasher.

Rob

[gspd]

Dude!

I love these type of problems in real life, but fixing them online is very tedious.

Some points to ponder; things that can have weird effects, trust me, I'm speaking from first hand experience
The spring loaded FLASH HI BEAM circuit may, by design on many models, have power even with the key off.
Some LED headlights have a high beam that goes on IN ADDITION to the low beam as opposed to INSTEAD of the low beam as BMW intended.
Some LED headlight units have ONE common ground for all functions, this may or may not be an issue.

Was the bike running and everything working perfectly immediately before you did this LED conversion?

If you are at the end of your rope, you could temporarily reinstall everything the way it was and see if everything works as it should. Then.... you can connect one circuit at a time until you determine the culprit.

[Rob Frankham]

Dude!

Some points to ponder; things that can have weird effects, trust me, I'm speaking from first hand experience
The spring loaded FLASH HI BEAM circuit may, by design on many models, have power even with the key off.

This isn't the case for this bike... the headlamp flasher is fed from the ignition switch via the 'non lighting' fuse, i.e. the fuse with the green - green/black wires connected to it.

Rob

[westonjezek]

Thank you, Team. I figured it out!

I'm used to vintage jap bikes that don't have a fuse box, so that was the last thing I checked. Turns out I had two blown fuses (Thanks Rob!). Easy fix...or so I thought. I took up GSPD on the single ground and it checked out. tested all connections and discovered that the flasher relay is also a suspect with a missing spade. With new fuses and a new relay I should be good to go!

Now I just need to figure out what LED relay would work to solve the hyper blink due to low LED resistance - a 2 prong LED relay from Amazon causes the flashers to stay on when engaged...Any idea what relay I need?

Thanks for getting me back in the road guys.

[Rob Frankham]

On a '95 machine a LED specific 3 prong relay should work although, not knowing the spec of your headlamp unit, it's difficult to be sure. Does the seller of the headlamp not give any recomendations?

Rob

[gspd]

Westonjezek said:
Now I just need to figure out what LED relay would work to solve the hyper blink due to low LED resistance

I've been through this many times. My experience is mostly with old school stuff like ours, rather than the newer stuff that you can't do anything to without a laptop and scanner.
IMHO, the simplest (and cheapest?) way to have your turn signal system (and 4-way flasher system, if so equipped) function as BMW intended is to add a resistor in each LED flasher wire. Using a LED flasher unit may or may not cause havoc with your turn signal indicator (in the dash) and/or your hazard flashers. Any electronic supply shop will have the resistors you need for next to free.