keyed relay trigger source

[large-stache]

I was wondering where people get their keyed 12V source to trigger a relay for farkles?  I know some people use the running light or tail light.  Has anyone used the GPS plug at the headtube?  If so would it be possible to use that plug to also power a GPS without upsetting the CANBUS?

[dirtrider]

7 hours ago, large-stache said:

I was wondering where people get their keyed 12V source to trigger a relay for farkles?  I know some people use the running light or tail light.  Has anyone used the GPS plug at the headtube?  If so would it be possible to use that plug to also power a GPS without upsetting the CANBUS?

 

Morning large-stache

 

Not much will upset the Can Bus on a BMW motorcycle  as the Can Bus JUST transfers data information, it doesn't actually control anything. 

 

You can't use the tail light (shouldn't anyhow) as that is pulse width modulated (flashes on & off to control voltage).

 

Most use the running light wire as it works, is easy to access & it works. At least the running light wire is predictable with key-on, engine-on, & off.

 

You probably could use the GPS plug but that is also ZFE (computer) controlled so won't always turn  off promptly when key is turned off, about the same as using the accessory plug power wire (that is also ZFE controlled & can have a delay in shutting down).  

The GPS plug can be used to power a GPS but (personally) I don't like that option as it doesn't usually shut down promptly at key-off so some GPS units will power back on using internal battery  at  a delayed B+ shut-off. I also don't like my GPS to shut down at short stops (like fuel or lunch) as it messes with the stored track continuity  & route continuity. (some riders don't seem to care though)-- My  (personal)  GPS power preference is to power my GPS with fused battery direct B+ then manually control the GPS as far as power into it goes. 

 

You didn't say what year your hexhead is but on the later ones (maybe early also but I don't know that for sure) there should be a key-on controlled  circuit at the starter relay that some have used to trigger an accessory relay.   

[large-stache]

14 hours ago, dirtrider said:

 

 

 

You didn't say what year your hexhead is but on the later ones (maybe early also but I don't know that for sure) there should be a key-on controlled  circuit at the starter relay that some have used to trigger an accessory relay.   

Thanks for the info dirtrider.  Sorry I forgot to put year, its 2009 R1200RT.  

[dirtrider]

9 hours ago, large-stache said:

Thanks for the info dirtrider.  Sorry I forgot to put year, its 2009 R1200RT.  

 

Morning large-stache

 

Have you given it any thought yet on how you want your power relay & GPS system to operate?

 

Your 09 should have a yellow/black wire running to the starter relay that m-i-g-h-t work for key-on (added) relay 12v power. I haven't personally used that starter relay yellow/black wire but some riders have. (I haven't heard of any issues)

 

If you want to try the yellow/black starter relay wire then  be sure to use a test light or voltmeter first to verify correct  operation  for what you need. Also, I would suggest that you use an (added) relay that has a high resistance (low power draw)  pull-in coil as you don't want to over-tax that yellow/black wire as it is directly computer fed.  

 

  

 

 

[large-stache]

after reading dirtrider's comment about powering the GPS all the time, to avoid resets at fuel stops etc. I will be using constant feed for the GPS and adding relay switched output if/when I add driving/conspicuity lights.  I will probably add a keyed USB charge port to the glovebox for charging "things" while I ride. I will look at a relay with a diode across the coil to shunt any voltage spikes also. 

[dirtrider]

2 hours ago, large-stache said:

after reading dirtrider's comment about powering the GPS all the time, to avoid resets at fuel stops etc. I will be using constant feed for the GPS and adding relay switched output if/when I add driving/conspicuity lights.  I will probably add a keyed USB charge port to the glovebox for charging "things" while I ride. I will look at a relay with a diode across the coil to shunt any voltage spikes also. 

 

 

Afternoon large-stache

 

Probably better off using  a relay with a 'resistor' across the pull-in coil as a resistor will work either current direction (with a diode you have to be ultra careful of the polarity when installing  the relay.

 

Plus, most small square  (aftermarket type power relays) come with a resistor rather than  a diode as most do-it-yourselfers would pop that diode first usage.  

 

Main advantage to a diode is that it allow tons of relays to be used on the same vehicle  as there is less circuit load using  many diodes vs using many  resistors.

[greiffster]

On 3/20/2019 at 7:02 AM, dirtrider said:

 

You can't use the tail light (shouldn't anyhow) as that is pulse width modulated (flashes on & off to control voltage).

 

 

 

DR,

So I've got a Touratech Canbus Helper TPS15 on my GS and the trigger yellow wire is tapped into my taillight.  I''ve not had any issues as of yet. 

 

Can you expand on the issue of using the taillight to trigger the fuse block?

[dirtrider]

11 hours ago, greiffster said:

 

DR,

So I've got a Touratech Canbus Helper TPS15 on my GS and the trigger yellow wire is tapped into my taillight.  I''ve not had any issues as of yet. 

 

Can you expand on the issue of using the taillight to trigger the fuse block?

 

 

Morning   greiffster

 

The 1200RT uses a pulse width modulated tail/brake light so ONLY one wire running both the tail & brake light. The basic circuit pulses on/off/on/off/on/off/etc  to hold the tail light voltage to about 8 volts, then when the brake is  applied it applies a full 12-14 volts to bring the light on at full brightness. 

 

The GS can be slightly different as the very early  GS ran a conventional tail brake light with the later GS bikes  using the pulse width modulated rear light control (your 08 GS should be using the pulse width modulated rear light).

 

I'm not sure what Touratech is doing but IF they are using the rear pulse width signal to operate the control relay then they must have a special circuit that overlooks the pulsing voltage input & uses a voltage/yes or voltage/no type circuit as the input control circuit.

 

Are you sure it is tapped into rear taillight or is it possibly tapped into the rear accessory socket wiring?

 

Added: I just looked up the install directions for the ( Touratech Canbus Helper TPS15)  on the BMW GS & it shows to connect to the front 'side light circuit' not the tail light circuit.  (Now run the yellow cable along the wiring harness under the cockpit to the parking light (sidelight) connector plug)

 

Install instructions;      https://cdn.touratech-usa.com/01-044-0450-0-b.pdf

[greiffster]

1 hour ago, dirtrider said:

 

Are you sure it is tapped into rear taillight or is it possibly tapped into the rear accessory socket wiring?   

 

Yeah, I tapped it myself.  I re-wired the whole darn thing last year along with all the accessories to clean it up.  The PO just kind had wires everywhere.  The color diagram of the TPS15 actually says the yellow wire is "usually tapped to the tail light".  It looked clean and easy as the TPS15 sits in a tray under the seat towards the rear.

 

I don't want to have issues, but so far none.  I could easily re-tap it to the blue/green wire of the diagnostic plug, as its already routed under it.  I understand that to be +12v with key on?

[dirtrider]

1 minute ago, greiffster said:

 

Yeah, I tapped it myself.  I re-wired the whole darn thing last year along with all the accessories to clean it up.  The PO just kind had wires everywhere.  The color diagram of the TPS15 actually says the yellow wire is "usually tapped to the tail light".  It looked clean and easy as the TPS15 sits in a tray under the seat towards the rear.

 

I don't want to have issues, but so far none.  I could easily re-tap it to the blue/green wire of the diagnostic plug, as its already routed under it.  I understand that to be +12v with key on?

 

Morning   greiffster

 

See the 'added' to my above posting.  I looked up the (latest) GS install directions & they show to connect  to the side light NOT the tail light.

 

I know the ad says connect  to tail light but that was probably for the early (non pulse operated tail light) -- The latest install directions do specify side light connection so someone must have questioned their original tail light connection intent as being incorrect for the later bikes.

 

 

[greiffster]

Thanks DR.  I think I'll re-wire it just to make sure.

[Indy Dave]

7 minutes ago, greiffster said:

Thanks DR.  I think I'll re-wire it just to make sure.

 

19 minutes ago, greiffster said:

 

  I re-wired the whole darn thing last year along with all the accessories

 

 

[greiffster]

5 minutes ago, Indy Dave said:

 

 

 

I've seen your bike....You've probably got the Binford Canbus 8000 

[Buckster]

There is another option on relay power source.  This is how I wired the relays my 2006 RT.  I believe the wiring stayed the same until changed on the 2010 model.

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Posted April 30, 2007

Kurt, if you're looking for an accessory like switch relay activation point, I used the 0.35mm violet wire coming from the ignition switch (which is powered directly from the battery before going through any computer). This violet wire goes +12v when the ignition switch is turned to the off position (not steering locked) and stays hot when the ign switch is turned to the on position. I use it to be able to power my relays even though the ign switch is turned off. It does go off when the ign switch is turned to the steering locked position. This violet wire goes to the radio which is computer controlled to go off after about 20 mins. But the violet wire stays hot. The violet wire comes from the ign switch and runs around the left side to the steering head then behind the steering head across to the right side of the frame. There is a plug that it goes into there. If you have the radio or radio prep package, the violet wire will continue out of the plug to the radio case. I tapped into it (solder and heat shrink) while the fuel tank was off but I think you can get to it with the tank cover pieces off. If I remember correctly the plug was zipped tied down.

I like it because it allows me to keep accessories on even though the engine is turned off kind of like a car's accessory position. I would not power an accessory with it, only control a relay's coil.

Buckster

[lawnchairboy]

On my '06 I tapped the diagnostic plug under the seat and used that to power a blue seas marine fuse block.   Never had any problems in 12 years of owning it since the mod.  

[dirtrider]

48 minutes ago, Buckster said:

There is another option on relay power source.  This is how I wired the relays my 2006 RT.  I believe the wiring stayed the same until changed on the 2010 model.

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Posted April 30, 2007

Kurt, if you're looking for an accessory like switch relay activation point, I used the 0.35mm violet wire coming from the ignition switch (which is powered directly from the battery before going through any computer). This violet wire goes +12v when the ignition switch is turned to the off position (not steering locked) and stays hot when the ign switch is turned to the on position. I use it to be able to power my relays even though the ign switch is turned off. It does go off when the ign switch is turned to the steering locked position. This violet wire goes to the radio which is computer controlled to go off after about 20 mins. But the violet wire stays hot. The violet wire comes from the ign switch and runs around the left side to the steering head then behind the steering head across to the right side of the frame. There is a plug that it goes into there. If you have the radio or radio prep package, the violet wire will continue out of the plug to the radio case. I tapped into it (solder and heat shrink) while the fuel tank was off but I think you can get to it with the tank cover pieces off. If I remember correctly the plug was zipped tied down.

I like it because it allows me to keep accessories on even though the engine is turned off kind of like a car's accessory position. I would not power an accessory with it, only control a relay's coil.

Buckster

 

Afternoon Buckster

 

Doesn't that violet wire only go 'off' in the steering lock position (I think it only goes off in lock position).

 

That would eliminate using the circuit for a LOT of riders as a number of riders do not always want to turn bars & lock them when parking the bike due to being  able to move bike without having to turn  key on, to  tight storage clearance issues, to it's a pain. 

 

I can't remember EVER locking my bars  on any of my motorcycles.

[dirtrider]

34 minutes ago, lawnchairboy said:

On my '06 I tapped the diagnostic plug under the seat and used that to power a blue seas marine fuse block.   Never had any problems in 12 years of owning it since the mod.  

 

Afternoon lawnchairboy

 

I have heard of some using that Green/Blue wire in the diagnostic connector but I have been reluctant to tell anybody to use that as that is the alternator boost wire on some of  the GS bikes (so you wouldn't want to use it on the GS).

 

It is also controlled from  inside the very expensive ZFE module with (only) a very small transistor as the internal controller. It seems like it would be very easy to trash that transistor with any kind of a short & that circuit should definitely have a relay that has internal clipping to prevent back EMF from the collapsing relay coil  damaging the ZFE.

 

You don't seem to be having an issue but if you ever do it will be expensive.

[lawnchairboy]

No longer own the bike, but like I said, never had an issue.  Wouldn’t want to replace a ZFE.  

[Buckster]

Dirt Rider, you are correct that the violet wire goes off when the ign switch is turned to steering lock.  I don't take the key out of my motor when parked in my garage.  I turn the key to a position that is half way between the off and lock position.  That turns the violet wire off but leaves the steering lock free.  But it does not allow the key to be removed.  But it is in my locked garage.   On the road, I either leave the ign switch in the off position (gas station remove the key to unlock the gas tank, go into the store which keeps the radio/GPS on or when at motel, campground turn the ign switch to lock, remove the key, turning off the riding electronics.

Thanks for allowing me to explain.  Buckster