Author Topic: Constant power on high-beam wire w/ koso bep 3  (Read 379 times)

Offline Fraje

  • Motobrick Curious
  • Posts: 10
Constant power on high-beam wire w/ koso bep 3
« on: August 15, 2018, 02:24:53 PM »
Hi,
Looking for some help. I have connected a Koso speedo via a BEP 3. The issue is that my warning light for high-beam is always on. Seems like the white wire carry approx 5v when OFF and around 12v when ON. Guessing the 5v is enough to get the led to light up. So... is it always 5v on that wire or do I have a issue somewhere (I would except 0v)? Where to start searching? Anyone had similar issue?

This has become more urgent for me to solve as the vehicle inspection is coming up and here in Sweden there is a requirement to have a functioning warning light.

Have a nice weekend!
Br
Frans
  • Sweden
  • K100 -86, R90/6 -74

Offline Skunky

  • ^ Proficient Motobricker
  • Posts: 310
Re: Constant power on high-beam wire
« Reply #1 on: August 15, 2018, 10:22:01 PM »
Hi - This very much depends on where the 5v is coming from. Is it coming from the Bep output, or is coming from the Koso I would suggest removing the wire from the BEP and measuring the BEP output and the wire to the Koso separately. 
  • Derby GB
  • BMW K100lt
Rebuild it and they will come..
90 K100lt
Triumph Thruxton 900
Honda CB400F

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 1776
Re: Constant power on high-beam wire
« Reply #2 on: August 16, 2018, 03:47:34 AM »
The BEP 2.0 had Pin 15 of the OEM connector go directly to Pin 2-10 (Fernlicht) on the BEP output; there was no other circuitry involved.  I would guess that BEP 3.0 is wired in the same way to the HIB output.  Therefore, it's hard for me to imagine that the BEP is the cause of this problem.  However, it is strange that you are reading 5V on the high beam indicator input to your gauge.  That voltage is not a common one on a vehicle and should not be present on the headlight circuit but it is a voltage which is found inside the BEP. 

I'm assuming that you are probing between the HIB output on the BEP 3.0 and a ground point on the motorcycle.  Is that a correct assumption?

Do what Skunky recommends first.  That will eliminate either the gauge or the BEP as a potential cause.

Do you measure the same voltage between ground and the white wire on the left hand controls connector under the tank with the high beam switch off (i.e. its normal position)?  If not, then there is something up with the BEP.  If you do, then there's something wrong further upstream with the switch.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/
2011 Moto Guzzi V7 Racer

Offline Scott_

  • Forum Moderator
  • ^ Quintessential Motobricker
  • Posts: 1856
Re: Constant power on high-beam wire
« Reply #3 on: August 16, 2018, 06:45:10 AM »
If you don't find anything with above suggestions, you might check how good the ground wire is for the headlight. If you have a connection going bad/weak, you could be seeing some voltage backfeeding from the light when on low beam looking for a path to ground.
  • My Garage
Ride safe.


1997 K1100LT 0302488
1995 K1100LT 0302044
Garmin StreetPilot 2820
Garmin Zumo 550
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Fraje

  • Motobrick Curious
  • Posts: 10
Re: Constant power on high-beam wire
« Reply #4 on: August 16, 2018, 12:06:10 PM »
Hi,
Thanks for the input so far.
Perhaps i was unclear, i have meassured the 5v on BEP HIB output aswell on the input wire (both between each + and ground), i.e suspecting issue to be upstreem so to say.  Will test headlight. Should I also look in the left-hand light switch/control?
Cheers!
  • Sweden
  • K100 -86, R90/6 -74

Offline DEcosse

  • Motobrick Curious
  • Posts: 23
Re: Constant power on high-beam wire
« Reply #5 on: August 16, 2018, 01:40:39 PM »
Are you by chance using an LED Headlight module?
If so, that voltage is likely bleeding back from that. I've seen this before on other bikes that have installed Chinese LED headlight with the exact same symptom and voltage.
If you connect a resistor between the white wire and ground, that should clamp it.
1k ohm 1/4W will be fine.
(you can connect it anywhere on the high beam circuit - but directly at the lamp connector is probably simplest - or at/inside your BEP since it passes through there too)
  • CA, USA
  • Triumph Daytona 955

Offline Fraje

  • Motobrick Curious
  • Posts: 10
Re: Constant power on high-beam wire
« Reply #6 on: August 17, 2018, 03:09:44 AM »
Are you by chance using an LED Headlight module?
If so, that voltage is likely bleeding back from that. I've seen this before on other bikes that have installed Chinese LED headlight with the exact same symptom and voltage.
If you connect a resistor between the white wire and ground, that should clamp it.
1k ohm 1/4W will be fine.
(you can connect it anywhere on the high beam circuit - but directly at the lamp connector is probably simplest - or at/inside your BEP since it passes through there too)

Hi,
The headlight is not led, but might be a change to be done down the path.
Will backtrack the 5v and see where I end up.
Br, Frans
  • Sweden
  • K100 -86, R90/6 -74

Offline DEcosse

  • Motobrick Curious
  • Posts: 23
Re: Constant power on high-beam wire w/ koso bep 3
« Reply #7 on: August 17, 2018, 09:53:12 AM »
1. If you disconnect the Koso Hi-Beam wire from the output of the BEP do you still get the 5V on the white wire at the input?

2. what happens if you disconnect the connector plug at the headlight itself? Do you still have the 5V or does it go away?
  • CA, USA
  • Triumph Daytona 955

Offline DEcosse

  • Motobrick Curious
  • Posts: 23
Re: Constant power on high-beam wire w/ koso bep 3
« Reply #8 on: August 17, 2018, 08:41:52 PM »
Here is a possible scenario that could cause this:

Have you possibly rewired the headlight?
Either at the lamp connector socket itself or at intermediate connector going to the lamp?

The two lamp filaments of course have a common 'ground' - there is no way to separate that.
When wired up correctly, with the High, Low and Ground to the appropriate terminals of the bulb, you get the scenario shown on the left of the diagram below.
Current will only flow through the Low Beam or the High Beam, whichever input is active.

IF however, the Hi and Ground wires to the lamp connector were swapped, you would get the scenario on the right side of the diagram.
What would happen if this were the case is that when the Low Beam is selected, the voltage would be divided across the two filaments and current would flow through BOTH of them
(you would get lower voltage across the High Beam Filament because it has lower resistance vs the Low Beam Filament)
That would ALSO give you approximately 5V OUT on the High Beam wire, enough to make the High Beam Indicator glow
Of course both filaments would actually be on in this scenario, but both with less intensity being at ~ 1/2 voltage on each.
So it might not look that odd.

Then when you go to the High beam, you would get the full 12V across the Hi Beam Filament and to the indicator Lamp
No current would flow through the Low Beam filament in this switch position, only the high beam (& indicator)

I obviously don't know for sure whether this is your problem, however if mis-wired like this, it would certainly give you that exact symptom
Worth checking!
(Simply unplugging the headlight connector will tell you if this is possibly the problem - if the 5V goes away and the LED goes off, it is because of this scenario)

(I've drawn it two different way diagrammatically but they are both the same electrically - not sure which one might be easier for you to follow - in either illustration simply stated the High Beam wire is connected to the Ground Terminal of the Lamp and vice versa)

 [ Invalid Attachment ]

 [ Invalid Attachment ]

 [ Invalid Attachment ]
  • CA, USA
  • Triumph Daytona 955

Offline Fraje

  • Motobrick Curious
  • Posts: 10
Re: Constant power on high-beam wire w/ koso bep 3
« Reply #9 on: August 20, 2018, 03:16:20 PM »
DEcosse, you are the MAN!!
Seems I had mixed up the HI ang GROUND. Now the wires have been corrected and the hi-beam warning light works fine. Unfortunately I had drained the battery so a test ride will have to wait until tomorrow.
Thank u all for you effort to help!!
Cheers!!
//Frans
  • Sweden
  • K100 -86, R90/6 -74

Offline DEcosse

  • Motobrick Curious
  • Posts: 23
Re: Constant power on high-beam wire w/ koso bep 3
« Reply #10 on: August 20, 2018, 03:19:28 PM »
Excellent news!
Enjoy the test ride!!
  • CA, USA
  • Triumph Daytona 955

Offline DEcosse

  • Motobrick Curious
  • Posts: 23
Re: Constant power on high-beam wire w/ koso bep 3
« Reply #11 on: August 20, 2018, 03:40:10 PM »
Incidentally I just installed one of the Chinese 'Daymaker' Headlight Modules on my friend's K75 for him - it looks pretty good for $50!
(there are dozens of these all variants of the same thing, on EBay or from AliExpress)
Probably not the quality of the Original Design JWSpeaker version, but it was an improvement over the incandescent lamp he had in the 7" bucket he had installed.

(Similar to this one - https://www.ebay.de/itm/7-Front-Scheinwerfer-50W-Hi-Lo-LED-Halo-Angel-Eye-Projektor-fur-Harley-Honda/283019806429?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D43785%26meid%3D56504a8a2c7e48c8b41c966f07ae3956%26pid%3D100005%26rk%3D5%26rkt%3D8%26sd%3D273314254366%26itm%3D283019806429&_trksid=p2047675.c100005.m1851 - but not that actual one)

I probably wouldn't have gone with the halo ring personally, but it actually looks quite good (the white anyway, not so much the Orange!!!!!)



  • CA, USA
  • Triumph Daytona 955

Tags: