HID & CANBus

[PatrickM]

So wired some some 35W HID's last night for my 2013 F800GS and received a lamp failure when I went to start the bike. No surprise there. Supposedly the system is expecting to see a load that's either not there, or greatly diminished.

One solution is to order 55W HID's such as a kit from DDM tuning, runs about $65. http://www.ddmtuning.com/Products/DD...rcycle-HID-Kit

Another is to wire in a load resistor to let CANBus believe there's adequate load on the system, runs about $25. http://www.KBcarstuff.com/CANBUS-Fix-p/cbfix.htm

The above two solutions are a no-go for many because the HID is there to free up additional power.

In a bunch of the HID systems I've worked with, they've always come with a relay, allowing the HID system to be wired straight to the battery, for whatever reason has been given. A relay to ground from the light circuit is isolated from the main circuit powering the 35W HID ballast, and is very easy to notice as being shorted.

So here are my questions:

Is 35W enough to inform CANBus that there is a load on the lamp circuit? I was thinking of wiring the HID circuit to the stock wiring (35W < 55W) and seeing if that were enough for CANBus

Any system using a relay should have <1W going through it, so shouldn't any wiring harness for HID w/ a relay trigger a lamp failure?

[ebrabaek]

Originally Posted by PatrickM

So wired some some 35W HID's last night for my 2013 F800GS and received a lamp failure when I went to start the bike. No surprise there. Supposedly the system is expecting to see a load that's either not there, or greatly diminished.

One solution is to order 55W HID's such as a kit from DDM tuning, runs about $65. http://www.ddmtuning.com/Products/DD...rcycle-HID-Kit

Another is to wire in a load resistor to let CANBus believe there's adequate load on the system, runs about $25. http://www.KBcarstuff.com/CANBUS-Fix-p/cbfix.htm

The above two solutions are a no-go for many because the HID is there to free up additional power.

In a bunch of the HID systems I've worked with, they've always come with a relay, allowing the HID system to be wired straight to the battery, for whatever reason has been given. A relay to ground from the light circuit is isolated from the main circuit powering the 35W HID ballast, and is very easy to notice as being shorted.

So here are my questions:

Is 35W enough to inform CANBus that there is a load on the lamp circuit? I was thinking of wiring the HID circuit to the stock wiring (35W < 55W) and seeing if that were enough for CANBus

Any system using a relay should have <1W going through it, so shouldn't any wiring harness for HID w/ a relay trigger a lamp failure?

I am not an expert on canbus, But my hid draws 33-35 watts, and I have never had any issues with the canbus. From reading numerous threads, I think it is more of an issue with " other issues" than the specific 55 watt draw needed, as mine clearly does not. I thought that the canbus would not detect a drop of 20 watt as a failure....but more like a NO DRAW...ie. burnt filament as a failure......It should be a simple test. Put in a 35 watt halogen in the headlight..... cost you 2-5 bucks..... if that does not create a failure... then there you have it. Worst case.... Buy a set of 10 watt led's....wire them into the circuit, and you are back at 55watt, and in case of that you are using both high and low beam hid.... now you can high bright someone, again.....

[PatrickM]

Originally Posted by ebrabaek

I am not an expert on canbus, But my hid draws 33-35 watts, and I have never had any issues with the canbus. From reading numerous threads, I think it is more of an issue with " other issues" than the specific 55 watt draw needed, as mine clearly does not. I thought that the canbus would not detect a drop of 20 watt as a failure....but more like a NO DRAW...ie. burnt filament as a failure......It should be a simple test. Put in a 35 watt halogen in the headlight..... cost you 2-5 bucks..... if that does not create a failure... then there you have it. Worst case.... Buy a set of 10 watt led's....wire them into the circuit, and you are back at 55watt, and in case of that you are using both high and low beam hid.... now you can high bright someone, again.....

Lol!

I actually grabbed some alligator clips and disconnected the positive to the relay (fused) and connected it to the hot from the lamp (w/ a 10A fuse to make sure I don't blow anything).

Worked. 5 times in a row. I went one step further then: Disconnected and removed the relay harness, plugged the ballast straight into the connector provided for the relay/H7 connector. Still no problems.

So... you're right. If there is a drop of 20W, it's not detected as a a failure.

Use a relay and you have a near 55W drop and that's a failure.

[Mtl_Biker]

Originally Posted by PatrickM

Lol!

I actually grabbed some alligator clips and disconnected the positive to the relay (fused) and connected it to the hot from the lamp (w/ a 10A fuse to make sure I don't blow anything).

Worked. 5 times in a row. I went one step further then: Disconnected and removed the relay harness, plugged the ballast straight into the connector provided for the relay/H7 connector. Still no problems.

So... you're right. If there is a drop of 20W, it's not detected as a a failure.

Use a relay and you have a near 55W drop and that's a failure.

So Patrick, you're saying that if you add HID headlights to the F800GS you should NOT be using a relay?

Upgrading the lights and adding extra lights (driving and fog as well as brighter and flashing LED brake lights) is one of my first priorities on my new 2013 F800GS when I get it. So I'm very interested in your experiences with this (as well as those of others).

As I get older, I find I enjoy night driving (car or bike) much less enjoyable and I need/want the brightest lights possible. On my car I have lights (I think they are Xeon) which actually turn left if I'm turning left, and right if turning right. They're superb. And my current bike (which I'm not replacing with the F800GS) has Xeon headlights which are excellent. I know the stock lights on the new F800GS won't be as good as I want.

Cheers!

[ebrabaek]

Awesome Patrick..... This is one of the few times that you don't need a relay, as there are no voltage drop to the element.....as it is stepped up to about 10000 volt, the little drop you get on the input side is negligible. This is what I did....

http://www.advrider.com/forums/showthread.php?t=624794

[PatrickM]

Originally Posted by ebrabaek

Awesome Patrick..... This is one of the few times that you don't need a relay, as there are no voltage drop to the element.....as it is stepped up to about 10000 volt, the little drop you get on the input side is negligible. This is what I did....

http://www.advrider.com/forums/showthread.php?t=624794

Nice setup! I actually was able to get the components mounted under the right fairing w/o much of a hassle (okay, was a hassle, but worth it). I do like looking through threads such as yours to determine what people have done and help figure out what install method I can go with.

Without pictures (for now), I was able to drill out two of the mounting holes on the ballast and mount it to the right side of the bike, right under the air intake. There are two screws there to hold the "frame" for the instrument cluster which were spaced nearly perfectly. From there, I used some extra-strong 3M dual sided tape to mount the igniter to the outside of the ballast. Ran the wires from the headlamp both over and under the "frame" to the ballast and back.

Pretty much kept things out of the way. One thing I do have to comment on are the newer components for HID are very different from the past. I pulled out a ballast/igniter/relay from my 4Runner and the ballast is easily 3x as heavy and 3x as large. The slim design for a 35W ballast is roughly the size of a pack of cigarettes - very nice!

Will try to get pictures up this weekend...

[TowPro]

Originally Posted by Mtl_Biker

So Patrick, you're saying that if you add HID headlights to the F800GS you should NOT be using a relay?


Cheers!

Your stock lights draw 55w each (I think). If you remove them, and use that wire to trigger a relay, then have that relay send battery voltage to your HID's, the BMW computer is only seeing the load of the relay (very small load). Thus it thinks the head light is burned out because the load is missing.

Now I never understood why someone would engineer a system that uses a resister (burns power) to "trick" the BMW computer into seeing a load, so they could then run the HID's off a relay connected direct to the battery.

50W resister load, + 35W HID load = 85W total.
That resister used do "trick" the computer into seeing the correct load eats as much power power as a piece of heated clothing