2015 RT: 12V lighting on aftermarket top case?

[2015 Blue RT]

I have bought a 47L aftermarket top case that has 2x LED lights on it. The wiring consists of a red and black wire. I tested it with +12V and it appears to be a tail light. I bought it in part due to a BMW owner's comment:

Quote

... the case is equipped with LED lighting with installed wiring. The nice part of the lighting is the CANBUS system on my 2016 K1300S adds amperage to the 2 wire tail light system to brighten the LED's thereby giving running light/brake light functionality to the lighting.

From an electrical standpoint, his comment confuses me due to supply amperage generally holding no sway over a lamp's output, whereas voltage would do so.

 

I have no way to contact the person that posted that, so I thought I'd post here and see what would be involved to replicate this on a 2015 RT. Reading another thread here, I see there is a top case connector on these bikes under the rear seat. I am still waiting for my bike to arrive, so this is all pre-planning.

 

Thanks for any advice.

[wbw6cos]

Can you post a photo of the lights on the case?

 

And maybe the wiring plug?

[dirtrider]

19 minutes ago, 2015 Black RT said:

I have bought a 47L aftermarket top case that has 2x LED lights on it. The wiring consists of a red and black wire. I tested it with +12V and it appears to be a tail light. I bought it in part due to a BMW owner's comment:

From an electrical standpoint, his comment confuses me due to supply amperage generally holding no sway over a lamp's output, whereas voltage would do so.

 

I have no way to contact the person that posted that, so I thought I'd post here and see what would be involved to replicate this on a 2015 RT. Reading another thread here, I see there is a top case connector on these bikes under the rear seat. I am still waiting for my bike to arrive, so this is all pre-planning.

 

Thanks for any advice.

Morning  2015 Black RT

 

That poster is a little confused but his observation is little more on point.

 

The CanBus has nothing to do with the tail/brake light intensity (most people don't understand what CanBus really is so they think it controls more than it does). The CanBus controlling the tail light is like saying the phone line into your house controls your house lighting). It could allow external control of lighting with the proper interface module or some electronics  but that module or electronics is what actually controls the lighting power & intensity not the phone line.

 

On the tail & brake light function, the rear light is pulse width modulated so the longer the pulse width the brighter the light (up to full system voltage). Typically the pulse width (pulse time on vs pulse time off) equals about 8 volts for typical tail light intensity then for brake light the pulse on goes to 100% on so it gets full system voltage therefore a brighter light.  

 

If the LED's in that rear case have the ability to get brighter or dimmer depending on input voltage (most do but some don't)  then it should follow the tail & brake light & run dimmer at the (8 volt nominal tail light pulse width) then get brighter when the rear light goes to 100% on at brake light function. 

[2015 Blue RT]

The seller's photo is attached.

 

The wiring has no plug, just 2x maybe 20 gauge wires.

[2015 Blue RT]

1 minute ago, dirtrider said:

Morning  2015 Black RT

 

That poster is a little confused but his observation is little more on point

 

The CanBus has nothing to do with the tail/brake light intensity (most people don't understand what CanBus really is so they think it controls more than it does). The CanBus controlling the tail light is like saying the phone line into your house controls your house lighting). It could allow external control of lighting with the proper interface module or some electronics  but that module or electronics is what actually controls the lighting power & intensity not the phone line.

 

On the tail & brake light function, the rear light is pulse width modulated so the longer the pulse width the brighter the light (up to full system voltage). Typically the pulse width (pulse time on vs pulse time off) equals about 8 volts for typical tail light intensity then for brake light the pulse on goes to 100% on so it gets full system voltage therefore a brighter light.  

OK, with that in mind, if I can connect to the lamp feed for the top case (presuming the under seat connector has that circuit), as well as the ground feed on the same connector, then this should work for both as it was written for the K1300S? I'm anxious to see the type of connector used, so I can see if a mating connector is available. That way I don't have to splice in to the harness. I understand wiring diagrams are not available for these bikes? If not, a little sleuthing with a multi meter should give me what I need there.

[dirtrider]

5 minutes ago, 2015 Black RT said:

OK, with that in mind, if I can connect to the lamp feed for the top case (presuming the under seat connector has that circuit), as well as the ground feed on the same connector, then this should work for both as it was written for the K1300S? I'm anxious to see the type of connector used, so I can see if a mating connector is available. That way I don't have to splice in to the harness. I understand wiring diagrams are not available for these bikes? If not, a little sleuthing with a multi meter should give me what I need there.

Morning  2015 Black RT

 

Basically yes, just keep in mind the rear light doesn't use a dedicated ground, it is a "low",  or basically a ground with a purpose as it returns to the controller then sees a common  chassis ground from that.  

[2015 Blue RT]

OK, thanks, that makes sense- which is why I wanted to keep the 2 wires on the dedicated circuit vs a chassis ground.

[dirtrider]

1 minute ago, 2015 Black RT said:

OK, thanks, that makes sense- which is why I wanted to keep the 2 wires on the dedicated circuit vs a chassis ground.

  Morning  2015 Black RT

 

OK, it sounds like you understand the system & what you need to do.  

[2015 Blue RT]

Well I hope so... the last BMW I rewired (for more power!) was an E34 estate for a Chevy V8. Ran OK, but never could get the AC to work...

[wbw6cos]

Interesting find on the topcase with built-in lights.   Kudos.

[Cap]

Skene has instructions on their website that explain various options for installing lights on BMW models.  One of the variations shows how to connect their product to enable tailcase lights to act as flashing brake lights.  See this page: Skene Instructions for Wetheads

 

First, I would highly recommend purchasing the Skene system.  But even if you choose not to buy from them, their instructions are helpful to identify the wiring.  Finally, if you do choose to buy a Skene system, you should be aware that there is a conflict between having their system act as both brake lights and turn signals, and whether you want your tailcase lights to serve as an auxiliary brake light rather than just a running light.  That is, the OEM BMW tailcase has a single light in the rear, and it can be used as a brake light but not a turn signal.  The Skene system with the auxiliary turn signals function cannot also power the single tailcase light as a brake light.  From Skene, you need to choose one or the other.  Don't buy the turn-signal version if you want to use your OEM tailcase as an auxiliary brake light.

 

Looking at your aftermarket tailcase, it seems to have two separate rear-facing lights, and it might be possible to connect them as both auxiliary turn signals and also auxiliary brake lights.  Perhaps the link I posted will give you some ideas.

 

Cap

 

 

 

 

[2015 Blue RT]

Thanks, I'll read up on that system.

I found a helpful YT video with my exact year/model/color. Looks like there is a 4-pin connector I need to ID for a mating connector.

 

 

 

[dirtrider]

Afternoon 2015 Black RT

 

That looks a lot like one end of the 10 pin GS-911 extension cable connector. You can usually find those GS-911  cables on E-Bay for $10.00-$12.00. (they seem to come & go) 

 

You need a better view of the motorcycle side but bottom is  the other OBD-II to GS-911 connector (looks close).

 

 

 

 

[92Merc]

Looks like the cable I bought off Amazon.  Convert my BT adapter to my 2015 diag port.

https://www.amazon.com/gp/product/B075K7MQFC/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

 

Since that picture of the pigtail, I've converted it back to stock so I can have central locking.

 

[dirtrider]

5 minutes ago, 92Merc said:

Looks like the cable I bought off Amazon.  Convert my BT adapter to my 2015 diag port.

https://www.amazon.com/gp/product/B075K7MQFC/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

 

Since that picture of the pigtail, I've converted it back to stock so I can have central locking.

 

Evening  92Merc

 

Yes, but it think he probably needs the other end (the side with the course screw threads on the outside it). Bottom picture in the post above. 

 

He needs to get the motorcycle in his hands then post up a picture of what is on the motorcycle, we can then help him (hopefully)  find the proper connector.  

[92Merc]

The actual BMW connector with the four flat and round end pictured cost me $187.  Not sure what current pricing is.  PN 61128548712

[2015 Blue RT]

That first cable is the OBD interface. I have ordered one of them for diagnostic work, but the connector I need is unrelated to that one. 92 Merc, great video, I am going to try to find just the connector. On the Japanese bikes I've owned, they often use Sumitomo connectors just like GM vehicles use Delphi connectors. I suspect being German, the connector brand may be Bosch. A site I have used to build Japanese harnesses is Corsa Technic. I see they sell Bosch connectors also.

 

The Max BMW site has repair connectors (pigtails) listed. Looks like many of them are around $20.

https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=56210&rnd=09082020

 

They have a couple of pics of the connectors from the harnesses. I'll attach one.

 

EDIT: This post on the Luxury Touring forum references the underseat connector, but it sounds like he cut it off and used Molex 150L connectors.

Quote

I did not use any of the existing wiring in the GTL case - just ran my new wiring along side it - and used Molex MX150L connectors to create a new connection for my top case wiring to connect to the bike underneath the seat.

 

A follow up post reports there is a $20-40 harness used on bikes w/o central locking (such as mine) for installing a powered top case. No one there was able to come up with a part #. The number listed is the $180 harness 92 Merc used.

[2015 Blue RT]

I bought the Haynes online manual and have looked at the wiring diagram for the top case. According to it, there are three wires in a connector (the 4-pin flat one?):

Pin 1, Brown, goes to (-) side of case interior lamp and brake light, comes from (-) side of battery and other items.

Pin 2, Red/Gray, goes to (+) side of trunk lamp switch, comes from (+) side of battery via fuse 1 (15A) and also instrument cluster.

Pin 3, not shown (unused?).

Pin 4, Gray/Black/Yellow, goes to (+) side of brake light, comes from "Basic module satellite (GMS) control unit".

 

These three wires are shown going to another connector (the round one?) as pins 1, 6, and 3 respectively. This aligns with a post I read on another forum, this was the round plug on a K1600BGA:

Quote

Pin 1 is Ground
Pin 2 is Positive Voltage to the charger port inside the case. 12V
Pin 3 is taillight (9.5V) then 12V for brake light when brakes are applied.
Pin 6 is cargo lamp inside case 12V
Pin 7 is radio amplifier 12V

 

Based on this, if I can make a t-harness for the aftermarket case, the red wire from it connects to the BMW Red/Black/Gray wire, and the black wire goes to the BMW Brown wire.

 

A picture is worth 1,000 words, I'm attaching a screenshot of the relevant portion.

 

[2015 Blue RT]

I took the lights in my case apart & saw they each have an LED strip light in them. I'm going to double down on these by installing 2x strips per side. I'm using these on Amazon:

https://www.amazon.com/gp/product/B015H90NBO

 

I plan to install them using some 3M double sided tape, and then run some automotive-grade wire from them to outside the trunk. The wires as they are have no protection, so I got some braided nylon sleeving and some clips to hold it in place. I've used this sleeving on car harnesses I've modified, it's good stuff. I'll figure out where it needs to exit and run it through a grommet.

[2015 Blue RT]

Did some work on the top case today. I found each lamp had 1 row of LEDs. One had a broken lead after I had pulled it apart, and the OEM bullet connectors looked sketchy- I didn't see wire to metal contact on one of the terminals.

 

I decided to rewire it for MORE POWER!

 

EDIT- I have decided to add a Skene IQ-260 controller so I can have a flashing brake light- a feature I had on my GSX.

 

I picked up a 4x 5050 x 6 LED strips (2 per side vs 1 OEM) that were about 4.5" long. They were about the same size as what was in there, but thicker. I used some silicone adhesive to hold them in place:

 

I then used some new bullet connectors (which is what the OEM setup used), and some 1/8 ID braided nylon sleeving where the wires were inside the trunk- they were bare as delivered. I really like this sleeving, I used it on a truck engine swap I did last year. Each side is removable connector wise, and the crossover cable connects to the wire going outside the case. I have since silicone sealed where the wires go to the lamps, and I used some quality Loctite glue to attach the wiring clips, as 3M 2-sided tape won't stick to the case very well. I also used automotive-grade TXL 18G wire to make the crossover and external harness, the OEM stuff was crappy vinyl.

 

Finally I used a variable voltage DC adapter to test the lamps. I couldn't hold everything well, so I only have one picture. They do dim @ 7.5~9V and are full bright at 12V.

 

T-minus 1 day for delivery of the bike, and I can see what is or isn't present there for case wiring.

[2015 Blue RT]

The bike arrived this morning, and I set the case in place to get an idea of how it will look:

 

 

 

I'm pretty pleased with it, as I plan to pull the bags and just use the case for my commute.

 

Most importantly, my bike has the 4-pin connector!

 

It has a plastic cap on it with some numbers that I have not been able to cross over as yet. Here are some pics with the cap off:

 

 

I'm hoping I can find a mating connector for this with some terminals and make my own harness for the case lights.

 

[2015 Blue RT]

Jackpot! I took a closer look at the connector on the bike, and saw the number 872-440-501 stamped on it.

Web searching found that it is a Hirschmann brand connector. So far, the closest place that has one in stock at a reasonable price is in China.

 

The mating connector is PN 872-536-501.

 

The best deal I found was the China site Aliexpress, where they sell it for $3.98 + $3.27 shipping to the USA. Estimated delivery was 12/20, so about 5 weeks. It comes w/ terminals and seals. Unless they hike the shipping a whole bunch, I may buy more than 1 in case someone else needs to do this.

 

EDIT- I bought 5 to get a discount & used their coupon, $22 shipped "expedited", should be here 12/5.

 

References-

According to this site, the connector is a Hirschmann brand, and the post has the mating part number.

Quote

Here are the original part numbers of Hirschmann
male 872-440-501 (4 way connector)
female 872-536-501 (4 way connector)

 

Edited November 12, 2021 by 2015 Black RT
Updated purchase info

[2015 Blue RT]

I filed down some 1.5mm Delphi terminals and wired the red LED wire to the GR/B/Y connector wire and the black LED wire to the BR connector wire. Ignition on, no tail light function (the bike tail light was on). The brake lights worked though. Apparently these LEDs don't play well with a reduced PWM signal. I used a DMM at the connector and saw 4.3 V with the ignition on, and 12.5 with the brake lever pulled.

 

I'll be interested to see if the IQ-260 controller makes a difference with them.

 

As a process update, the Loctite "Extreme Glue" did not hold, so I used some specialty Loctite epoxy # EA 9460 after scraping off the 2-sided tape and roughing up both surfaces (clips and case). It seems to be holding the clips in place. I also saw there was a small (maybe 1/8") hole in the bottom of the case for the wires to go through. It was too tight for both of my TXL wires, do I drilled a second one in front of it to keep them apart. I'll silicone seal and wrap them in braided nylon once the Hirschmann connector gets here.

[wbw6cos]

Are you planning on having a passenger?   Maybe it is the camera angle in the photo, but just be sure you have the topcase mounted far enough to the rear for a decent seating position for the passenger.

[2015 Blue RT]

It was just sitting on the rack in those pics. When I installed it, I placed it as far back as possible. The center rib of the OEM rack limits travel. I sat on the rear seat and it should be OK. I rarely have a passenger though. Now that I think about it it's been over 20 years since I've had one.

[2015 Blue RT]

The IQ-260 is installed and working. I decided to put it inside the case since there was room on the lid and it is really small. I used a Scotch double-sided pad. I'll attach some pics. Here's what I noted during the install:

The Skene directions said you could use the top case connector for +12V. On mine, it was hot all the time (tail lights would stay on), so I used the red/brown wire at the 2-fuse block under the rider seat. This connection option was also in their directions. What is odd about this is the circuit stays hot for 45-60 seconds after the ignition is off. The tail lights stay on during this time.

 

I used simple bullet connectors for the connections inside the case.

 

Programming was easy, I found there was no delay in the brake light turning off once the lever was released (the Skene directions warned of a delay). 4x activations, wait 5 seconds, top case lamps flash 4x, then I used mode 2 (2x activations) for 4x long flashes then steady on for brakes. I did find that my tail lights were in "conspicuity flicker" mode out of the box when they should have been normal brightness. I didn't see the need for this and shut it off by entering programming mode and then 7x activations. This did not affect the brake flashes.

 

Right now I'm still using filed down GT-150 male terminals in the BMW top case connector until my Hirschmann connector gets here- perhaps next week. For the +12V, I used a single-terminal Weatherpack connector. That way the case can still be removed via 2 connectors if desired.

 

EDIT- It occurs to me it would be a good idea to add in a mini fuse holder (Lowes link, <$3) in the wire from the tap. I have updated the PDF and diagram.

 

I'll attach a PDF and pic of my wiring diagram:

Adapter harness.pdf

 

 

Pictures-

IQ-260 installed on top lid and wired. I need to dress up the wiring some, I'm still having trouble getting the plastic clips to stick to the case

 

Top case connector 2x wires, Weatherpack 1x wire (note braided nylon sleeving)

 

Tap for +12V switched power

[Cap]

Nice work.  I'm glad you found the Skene stuff to be useful.  I think that same controller can be configured so that the lights might double as turn signals.  Did you consider it?

 

Cap

[2015 Blue RT]

Thanks, that is the next step up for adding turn signals. I did look at that one (IQ-260-TS, $85) as well as the top of the line w/ deceleration (IQ-260-D / D-TS, $100~$115), but decided my goal was simply to use these added lights as tail/stop. I think if I spend anything else light-related, it will be for added forward lighting.