Wiring help on fog lights

General discussion of the BMW R1200RT/R1250RT
Post Reply
jackronner
Posts: 506
Joined: Sat Oct 07, 2017 4:45 am
Location: Oakland, California
Has liked: 1 time
Been liked: 9 times
United States of America

Wiring help on fog lights

Post by jackronner »

What with the virus shut-downs, I don't think any help will be forthcoming from the manufacturer (Cree).  The problem is with the switch (no diagrams or installation instructions).  The lights have two thin stranded wires, as does the switch, and there's no easy way to add wires to the switch directly from the battery. The switch has an on/off button and, by repeatedly pushing the on switch, you can cycle thru three beam modes.  My plan (pls feel free to shoot it down in flames) is to splice onto the switch wires the respective neg/pos wires coming from the battery and the lights (I don't think the lights are self-grounding).  Of concern is a) whether I should use a slightly thicker positive wire to accommodate the combined current to both lights, and b) whether the lack of direct individual connections to the positive battery terminal will diminish the lights' brightness?  Any help appreciated, and stay healthy (I long for the days when the only viruses we had to worry about were of the computer and social media kind.  Seems the whole world has "gone viral").
User avatar
exportman
Posts: 291
Joined: Tue Sep 27, 2016 7:57 pm
Bike Model and Year: R1250RT 2023
Has liked: 6 times
Been liked: 41 times
Great Britain

Re: Wiring help on fog lights

Post by exportman »

Leds will only work one way around  test them against a battery  one wire to positive one to negative  if it works great  if not revers them  the switch is most probably a simple on off  one side power from the live feed  the other side the feed to the positive on your lamps
jackronner
Posts: 506
Joined: Sat Oct 07, 2017 4:45 am
Location: Oakland, California
Has liked: 1 time
Been liked: 9 times
United States of America

Re: Wiring help on fog lights

Post by jackronner »

I'm pretty sure you're right about the switch essentially delivering/interrupting the positive side.  But I guess they just expect the user to either rig a wire from the two negative light wires directly to the battery negative, or to ground them to the frame or splice them onto a known ground wire from another system.  They didn't even provide instructions in Chinese!!  Thanks for the response.
User avatar
exportman
Posts: 291
Joined: Tue Sep 27, 2016 7:57 pm
Bike Model and Year: R1250RT 2023
Has liked: 6 times
Been liked: 41 times
Great Britain

Re: Wiring help on fog lights

Post by exportman »

If you are wiring these up without a canbus connector I would suggest you wire it through a relay.  I used the aux socket feed for the switch side of the relay


The you can't leave them on with the ignition switched off ( power is cut to the aux socket after about 20 seconds  then the lights would auto off)
jackronner
Posts: 506
Joined: Sat Oct 07, 2017 4:45 am
Location: Oakland, California
Has liked: 1 time
Been liked: 9 times
United States of America

Re: Wiring help on fog lights

Post by jackronner »

Exportman,  Sage advice (which I hadn't considered) that will probably save me from many dead batteries.  Cheers.
jackronner
Posts: 506
Joined: Sat Oct 07, 2017 4:45 am
Location: Oakland, California
Has liked: 1 time
Been liked: 9 times
United States of America

Re: Wiring help on fog lights

Post by jackronner »

A bit of a warning, at least about the Cree lights I bought.  Tho' the beams themselves are quite good, there is no mechanism to adjust them up and down.  Can't believe they omitted this, since this is critical for avoiding blinding oncoming cars. On my 2009 RT, I had to completely jury-rig the attachment to the lower forks despite their advertised claim that it's compatible for my bike, and without the adjustment their backward rake points the lights into the trees.  I chose to remove the backmost of two horizontally aligned  screws attaching the lights to the clamps so I can swivel them up and down.  I'll let you know if this doesn't work.  BTW, no response to my questions from Autodaby (maybe its Corona),the middleman for these lights, but some reviews on their site didn't care for the flashing light function, mostly because you have to cycle the on/off switch between three modes.  Since, when lane-sharing during the day, I already put on my bright beams, the flashers can only help to announce my presence to drivers ahead, so I think it's a good option.  And Exportman, I took your advice and plugs the switch into the auxiliary port on the left side of the fairing, but apparently it doesn't shut off when the key is in the off position.  Unlike my 2005 RT, I noticed there is no rear power port.  I'm thinking of splicing them onto the low beam wire on one side.
Last edited by jackronner on Sun Mar 22, 2020 1:50 am, edited 1 time in total.
User avatar
exportman
Posts: 291
Joined: Tue Sep 27, 2016 7:57 pm
Bike Model and Year: R1250RT 2023
Has liked: 6 times
Been liked: 41 times
Great Britain

Re: Wiring help on fog lights

Post by exportman »

HI


On mine the circuit takes about 2 - 3 mins to shut off after removing the key but I'm on a 2017 model  If you bike is on a Canbus I would avoid splicing wires, from my experience it just generates lots of errors.


The Aux socket may be current sensing and remain powered it there is sufficient draw, but a correctly wires relay should draw next to nothing from the witch circuit,  all the current to the devices would be from the battery so it should not interfere.
jackronner
Posts: 506
Joined: Sat Oct 07, 2017 4:45 am
Location: Oakland, California
Has liked: 1 time
Been liked: 9 times
United States of America

Re: Wiring help on fog lights

Post by jackronner »

Exportman,  It turns out the 2009 handbook says the aux ports stay on for 15 mins (can't figure out to what purpose) which I'm figuring would be a drastic drain on the battery.
Post Reply