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Wiring modification: Automatic turn on of low beam lamp after engine startup


Skipper

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Does anyone know of or, have they built an "automatic" low beam headlamp switching device to incorporate in standard wiring of an older machine that was built before automatic switching?
The problem is not a simple one for older bikes due to the lack of suitable computer wizardry 
For a start, one does not want the lamp turned on with the ignition since this draws voltage away from the starter, if you are lucky enough to have one, so perhaps several seconds timed "post ignition" would be good?
Then the next issue is for those with a dual filament bulb - what happens when you want high beam (at night) and turn on using the light switch on the handlebars? I think a fried lamp would be the outcome without some means to shut down the "automatic" circuit - due to the two filaments overheating.
Add to this, any system would be better served if one could find the appropriate solid state relays to save both the additional permanent "load" on the electrics, and achieve the higher reliability of modern electronics. I see the Chinese build one with an "adjustable timer", but of what quality standard I am unclear?  I'm thinking it would need to switch 12 VDC at about 5 amps.

 

I know we all had manual switches to turn on the headlamp before any of this sophistication was thought of but when one changes from a modern machine to ride one of the older members of one's collection, it would just be one less thing to remember - and that's just nice
 

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Some smart factory engineers have thought of these questions and devised some clever solutions. 
 

Dual Filament Bulbs - take look at this wiring diagram of left-hand controls. From different bike, so colours may be different, but wiring is exactly same.

 

uc?export=download&id=1oPDYW_UGPgZEgu5mm
 

Dimmer switch (3) is SPDT with power coming in on BL/Y wire

LO position - sends power out R/Y wire to low-beam filament

HI position - sends power out R/BK wire to hi-beam filament

 

Note that dimmer switch can ONLY be connected to ONE output terminal at a time. When in LO position, it powers low-beam filament. When switched to HI position, switch disconnects power from low and connects it to high-beam filaments. It's impossible for such switch to power both filaments at same time. Logically, it's an OR circuit.

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13 hours ago, Skipper said:

Does anyone know of or, have they built an "automatic" low beam headlamp switching device to incorporate in standard wiring of an older machine that was built before automatic switching?
The problem is not a simple one for older bikes due to the lack of suitable computer wizardry 
For a start, one does not want the lamp turned on with the ignition since this draws voltage away from the starter, if you are lucky enough to have one, so perhaps several seconds timed "post ignition" would be good?
Then the next issue is for those with a dual filament bulb - what happens when you want high beam (at night) and turn on using the light switch on the handlebars? I think a fried lamp would be the outcome without some means to shut down the "automatic" circuit - due to the two filaments overheating.
Add to this, any system would be better served if one could find the appropriate solid state relays to save both the additional permanent "load" on the electrics, and achieve the higher reliability of modern electronics. I see the Chinese build one with an "adjustable timer", but of what quality standard I am unclear?  I'm thinking it would need to switch 12 VDC at about 5 amps.

 

I know we all had manual switches to turn on the headlamp before any of this sophistication was thought of but when one changes from a modern machine to ride one of the older members of one's collection, it would just be one less thing to remember - and that's just nice
 

Hi Skipper.

Just to be sure. Is your wiring the same as this wiring diagram ? If it is, the headlight power is removed As you press the Starter Switch and then returns power on release of the switch!

So No, the lights aren't drawing power away while cranking the engine.

This is basically the same functionality of both 5th and 6gens but using relay function to switch light power. Yours does it directly by the Dimmer Switch and Starter Switch action. So, is it really anything to worry about?

There is no "computer wizardry" or "automatic switching" of lighting power in later VFRs, simply switches and relays!

The bottom line is, and this goes for all modern VFRs. Switch On and start the engine, otherwise leave Ignition Off.

AND when stopping the engine use the Ignition Switch not the Kill Switch, this will avoid leaving the headlights burning while Ignition is still On.

Hope this helps?

 

1986_VFR750F-WiringDiagram.png

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2 hours ago, Skipper said:

Add to this, any system would be better served if one could find the appropriate solid state relays to save both the additional permanent "load" on the electrics, and achieve the higher reliability of modern electronics.

 

What is this "permanent load" you're talking about that solid-state relays would save?

 

Why would solid-state relays place less load on electrical system? Power consumed (load) is determined by devices being powered by relays. Low-beam filament consumes 55w. High-beam filament consumes 60w. Doesn't matter if it's mechanical or solid-state relay doing the switching, they will still have to pass exact same amount of power to bulbs. And electrical system will still need to generate and flow exact same amount of power with either type of relay.

 

Solid-state relays have many benefits: faster switching times with less electrical noise & static, higher power-transmission in smaller size, cooler operation. But power-savings isn't one of them.

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A mechanical relay draws current to activate the -magnetic coil, small I'll grant but considerably more that the mA used to activate a solid state. When I looked at how I might wire such a circuit on my '89 VFR I could see no less than two separate relays required. This was one of the reasons I asked the forum - I'm not an expert, just someone trying to solve a problem.

The electro/mechanical relay can be responsible for considerable voltage spikes back into the wiring when it is switched off (mentioned by Danno), just another risk to the venerable old electronic ignition in the early bikes and does need to be considered when modifying any circuit - there are ways to protect but just another issue I read about.
As for the other answers, I shall need to check the Gen 2 wiring diagram and see what it looks like regarding the lights/starting sequence - if I'm smart enough?

Thanks to you both for your replies, I have certainly got some homework to do now and it looks like the answer is there with a bit of figuring 

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Skipper if your bike has just the one headlight bulb with the two filaments, the drawing supplied should be similar, its for an 86 VFR750.

 

Do a simple Test. When you crank the bike over, your headlights should be OFF when you release the Starter Switch the headlights should be back ON.

 

Because you are only working with one bulb the current draw didn't require the addition of a relay.

As mentioned the headlight function is the same as later gens. Its only the addition of extra bulbs and the greater current draw that necessitated the use of Hi and Lo beam relays.

 

Your concern for relay spike on your old bike (if you decided to fit one) is nothing to worry about. The spike potentially generated by your starter relay would be far more significant compared to what a smaller relay used for a lighting circuit. A simple flyback diode mounted across the relay coil would solve this, but in this case, just not needed,

 

I think you have nothing to worry about! If you turn Ignition to on then fairly soon start the engine and turn the engine off via ignition switch not the Kill Switch, you won't have a problem.

 

Making sure your Battery and Charging System are Good is far more important than your lighting concerns.

 

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Thanks Grum. Right now the bike is in bits going though restoration so can't try anything just yet, however am making copies of all feedback and will implement something at the appropriate time. Seems it was not as big an issue as I had thought - me over thinking things again.

I have just about completed the repairs on the fairings which were in poor condition but will ultimately be done in the '86 Honda Interceptor red, white and blue color scheme, just 'cause I like the combination and I should be seen - not run into! (It's a safety thing - like with the daylight headlamp on)

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You need 2 relays. One normally open the other normally closed. Find the feed or return wire from the bulb you want to control & place both relays load circuits in series in the wire. 
 

Connect normally open control circuit to a switched circuit as in only powered when the ignition is on. Thus turn ignition on & the bulb will illuminate. 
 

Connect the normally closed control circuit to the starter relay circuit, such that when you press the starter button it will open & remove power to the bulb, freeing the juice for stating duty. When engine starts & starter button is released it will reconnect & power the bulb. 

 

Simples 😁👍

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6 hours ago, Mohawk said:

You need 2 relays. One normally open the other normally closed. Find the feed or return wire from the bulb you want to control & place both relays load circuits in series in the wire. 
 

Connect normally open control circuit to a switched circuit as in only powered when the ignition is on. Thus turn ignition on & the bulb will illuminate. 
 

Connect the normally closed control circuit to the starter relay circuit, such that when you press the starter button it will open & remove power to the bulb, freeing the juice for stating duty. When engine starts & starter button is released it will reconnect & power the bulb. 

 

Simples 😁👍

 

Agree that will work. But why go to all that trouble of fitting relays when he already has that exact switching action?

 

He only has one dual filament bulb. Hi or Lo (depending on dimmer switch position) will be on at switch on and the starter switch when pressed disables either selected beam.

 

Maximum current draw on Hi beam is only 5amps the OEM switches will easily handle that and no doubt why Honda didn't add the complication or need for relays.

 

The main concern for Skipper was to not have any light On with Ignition to On prior to starting, but, he was unaware the Starter Switch removes lighting power when pressed to maximize cranking. He now states.....

"Seems it was not as big an issue as I had thought - me over thinking things again".

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Err appears I misread the request. Older bikes up until at least 6th gen had manual headlight switch well in Europe anyways. I hate my newer bike has lights always on for the sake of saving the manufacturer pennies to add a manual switch ! 
 

But I'm a dinosaur & disable all the lawyer based stand cutouts etc, solutions to problems that don't exist. Idiots do idiotic things, thats fine by me 😂

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I thought the removal of the On/Off headlamp switch was a legal requirement, not manufacturer based. 

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Certainly for US markets, headlights always-on was legal requirement. From US Code of Federal Regulations. Any one know of similar in EU?

 

Title 32 - § 636.28 Special rules for motorcycles/mopeds

(d) Motorcycles/moped headlights and tail lights will be illuminated at anytime the vehicle is being operated.


Could be Honda wanted to cut costs and offer single "World" model of bikes?

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40 minutes ago, DannoXYZ said:

 


Could be Honda wanted to cut costs and offer single "World" model of bikes?

It was all makes & models at the same time over here which is why I figured it was a legality change. 

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On 12/1/2022 at 1:46 PM, Skipper said:

A mechanical relay draws current to activate the -magnetic coil, small I'll grant but considerably more that the mA used to activate a solid state. When I looked at how I might wire such a circuit on my '89 VFR I could see no less than two separate relays required. This was one of the reasons I asked the forum - I'm not an expert, just someone trying to solve a problem.

The electro/mechanical relay can be responsible for considerable voltage spikes back into the wiring when it is switched off (mentioned by Danno), just another risk to the venerable old electronic ignition in the early bikes and does need to be considered when modifying any circuit - there are ways to protect but just another issue I read about.
As for the other answers, I shall need to check the Gen 2 wiring diagram and see what it looks like regarding the lights/starting sequence - if I'm smart enough?

Thanks to you both for your replies, I have certainly got some homework to do now and it looks like the answer is there with a bit of figuring 

You're welcome! 🙂

I think you need to hands dirty with actual real-world testing of components to gather data. Then your understanding of them will match reality. Such as how headlight dimmer-switch alternates between high & low-beam filaments without overheating issues. Same thing with solid-state relays; not end-all solution for bikes. 

 

One of most commonly used mechanical relay is Bosch 5-pin and its activation-coil consumes 30ma to trigger. It's widely used in all sorts of demanding motorsports applications and is much more durable & reliable than Honda's relays due to sealed construction and coated terminals.
uc?export=download&id=1EkynPIDly7LmXE6SE

 

Solid-state relays... are different than transistor switches or op-amps. They require isolation between input vs. output legs; commonly done through an opto-isolator.

uc?export=download&id=1GD-xUV3cB5GPUnG8M

 

A commonly used solid-state relay is MOC3020 unit. Combined activation-power consumed, including LED comes to 1000ma!!! Or about 34x more than Bosch mechanical relay.

uc?export=download&id=1_jCTsjbR8RMGwo3gv

 

As with most things, there are no "universal truths" about anything. It all depends upon specific components and how they're implemented.

Way back in 1986 Kawasaki came up with delayed headlight circuit requiring only ONE relay. Similar to Honda's ingenious fuel-pump relay controlled by ignition pulses. Which can't be used to power headlight due to variable duty-cycle of pulses; headlights will be dim at idle and increase brightness as RPMs increase. This is incredibly amazing solution to providing variable volume of petrol to carbs to match usage demands. I'll explain Kawi's headlight circuit next after working up some diagrams...  absolutely zero need to re-invent the wheel to implement this feature...

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On 12/1/2022 at 12:02 AM, Skipper said:

Does anyone know of or, have they built an "automatic" low beam headlamp switching device to incorporate in standard wiring of an older machine that was built before automatic switching?
The problem is not a simple one for older bikes due to the lack of suitable computer wizardry 

...

I see the Chinese build one with an "adjustable timer", but of what quality standard I am unclear?  I'm thinking it would need to switch 12 VDC at about 5 amps.

 

I know we all had manual switches to turn on the headlamp before any of this sophistication was thought of but when one changes from a modern machine to ride one of the older members of one's collection, it would just be one less thing to remember - and that's just nice
 

Ok, let's take a look at Kawasaki's 1986 headlight circuit. It uses single-relay and doesn't turn on headlight until engine is running!!! So when you turn key ON, clocks will light up, marker-lights, tail-light and ECU will get power. But headlight stays OFF. Then when you start engine, headlights turn ON, wow!!! No complex timer circuits, no computers needed... this is why EEs get paid big bucks!

 

A. So headlight circuit starts like any other bike, power comes from battery through main fuse to ignition-switch. When ignition-switch is turned ON, power goes to headlight-relay... BUT... instead of connecting to its activation-coil and turning ON headlights, it goes to power-input terminal of relay and just sits there... doing nothing... huh????
uc?export=download&id=1rV6kM4hyWWmObUdjQ

 

B. Power just dead-ends at headlight-relay, so how the hell do you turn headlights on? Just start engine!!! At which point, AC-output of one of stator-phases goes towards headlight-relay, through diode to get converted to pulsed DC, and through activation-coil and turns on relay!!! Incredible!!! Whoever invented this circuit should get Queen's Award!!!

uc?export=download&id=1ZQUZQRklHxjzLZnIo

 

C. With headlight-relay activated, power goes from input-terminal to output-terminal and through dimmer-switch to power headlight. Either low or high-beam depending upon switch's position. Business as usual here....

uc?export=download&id=1l_P1zw1FBdSd8qLSb

 

D. But wait, there's more!!!! If you look at output-terminal of headlight-relay, it branches off to 2nd circuit. Eh??? This 2nd circuit goes through diode and goes back through relay's activation-coil. It's self-activated itself (latch) and stays ON for good! This latching is to make sure relay stays ON and not pulse headlight like output from stator would do. Makes for more durability and longevity of relay since it's not getting repeatedly turned on & off with each engine revolution. Only when you turn ignition-switch OFF, will relay be deactivated and headlight turns off

uc?export=download&id=1rJrVocCc84ATMc30G

I recently retro-fitted this circuit to my CBR600RR and VFR750F (requires just two diodes, some hook-up wire and re-pinning of headlight-relay socket). 

 

There's really nothing new under sun. Anything you can think of, someone else has already thought of it and found solution. I recently considered working up microcontroller/Arduino circuit to convert my car's 5-wire taillight/brake/turn-signal wiring into 4-wire output for my motorcycle trailer.  Then I figured someone had already done this. Found complicated circuit using numerous diodes, zener-diodes, resistors and power-MOSFETs... WTF??#$@&! A little more research found much, much simpler circuit needing just 4 relays, winner!!! 🙂

 

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On 12/2/2022 at 11:24 PM, Grum said:

 The Fuel Cut Relay is the only device detecting engine running via the Tacho output from the Spark Unit. Assuming his bike matches the drawing supplied above!

So does the oil pressure switch. I used it to trigger some xenon bulbs. Using the regular starter switch circuit they sometimes would not ignite due to too low voltage after releasing the starter.

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1. US Honda models use a starter switch which momentarily breaks the headlight circuit when the starter button is pushed, thus allowing the battery's power to go exclusively to the starter circuit.  ROW starter switches are just simple 2-pole switches, so something more fancy would need to be added to accomplish the same thing.  Me, I'd see about finding a US-market switchpod for the bike and go from there (additional wiring and connectors with more pins would be required to duplicate the US-spec circuit.)

 

2. European Hondas switched over to always-on headlights around 2003, IIRC.  However, unlike in the USA, it wasn't a regulation, it was a manufacturing harmonisation decision.

 

Ciao,

 

JZH

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18 hours ago, JZH said:

1. US Honda models use a starter switch which momentarily breaks the headlight circuit when the starter button is pushed, thus allowing the battery's power to go exclusively to the starter circuit.  ROW starter switches are just simple 2-pole switches, so something more fancy would need to be added to accomplish the same thing.  Me, I'd see about finding a US-market switchpod for the bike and go from there (additional wiring and connectors with more pins would be required to duplicate the US-spec circuit.)

 

2. European Hondas switched over to always-on headlights around 2003, IIRC.  However, unlike in the USA, it wasn't a regulation, it was a manufacturing harmonisation decision.

 

Ciao,

 

JZH

Interesting.

 

I always thought that it was regulation in Europe as I believe, though I could easily be wrong, that all manufacturers changed to always on headlamps in the same model year, 2006. If they all did it at the same time, it would suggest regulation rather than harmonisation.

 

Happy to learn the truth though.

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Sorry, I don't recall the details anymore, but it was discussed quite a bit on the HondaVFRClub forum at the time.  Maybe I got it back-asswards?  :unsure:

 

Ciao,

 

JZH

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