Extra Headlight - Where to get energy from

[Adamastor]

Hi there!

My R65 "dashboard" has those two electric switches (former police force bike, so I guess they would control the siren and the emergency lights), and a friend of mine offered me a headlight I was willing to use on the R65.
I would like to ask you where should I get the power for this headlight from, I would like it to be off when the ignition key is not on (to avoid someone to turn it on when it is parked on the street), but I am not sure where to go get the power from... Dont want to blow fuses and so
Does any of you experienced R65 users know what's the best spot to go plug it in?

Regards,

Sergio

[Bob_Roller]

Your best method, would be to wire it directly from the battery, install a fuse in the 'hot' wire, the wire coming off of the positive terminal of the battery, use a relay to handle the 'load' power to the extra headlight, use a 'switched' power source (one that only has power to it when the ignition switch is in the 'ON' position),  to the switch on the instrument cover, to operate the relay .

With the bike being a former police bike, the switches may already be wired to do this .

I have never seen a wiring diagram for the police accessories, so I can't give you much more advice where to go from here .

[Adamastor]

I have some strange stuff (like what looks like a potentiometer) under the tank, and have never explored very well what most are for.
Unfortunately the two dashboard switches have no conections and I would have to solder them.
The method you have explained seems pretty good and safe, I will try to find a good 12v switch and try to find a power source that only powers up with the key in. I actually have a 5v switch at home, but I doubt we have 5v power in any of our R65 conections...

thanks for the advice...

[nhmaf]

You should be able to get a switched power connection back at the headlight relay.  I'd try to put your relay  in the "spare" relay area on the backbone beneath the fuel tank, and just wire the  ignition switched power line from the original relay up to your switch on the dashboard, and back to the new relay coil.

Depending on wattage - you'd best only use the extra headlight when driving at good speeds on the open road unless you have one of the higher output alternators/charging systems, otherwise the "normal" 280W charging system may not be able to keep up if just putting about in town.

[Rob Valdez 79 R65]

My guess on the potentiometer, is, a variable voltage regulator.  I have heard of some police bikes having them.
Does it look like that is where the knob is located?

What year is your bike?  They changed over the years.

[bruce_launceston]

You won't need to find a 'key on only power circuit' if you wire it up so that it switches with the bikes high beam (you can install a override switch in the 'switch' wire from the headlight circuit to the relay.

Your extra headlight (driving light) will come on exactly the same as your high beam and can't be switched on unless the key is on and the headlights are on high beam.

This is standard driving light wiring, and exactly as Bob described above but if you need it more graphically do a google search for wiring an auxillary driving light on any early vehicle (some modern vehicles switch the headlights through the earth which complicates things).

[Adamastor]

Hi there, and thanks for the replies.

Wiring this extra light to the headlight high beam wont overcharge the system? (both headlight high beam and extra beam will be on at same time)

Dont want to melt wires because of too much heat...

Regards,

Sergio

[Lucky_Lou]

Im considering an LED bar under my headlight this will have the desired safety effect use very little power and i thought i would feed it from the horn circuit no need for relays ect...i  currently ride with headlights all the time so this should help with charging ect i have no seat lock so if necessary i was going to fit a switch there.
Lou

[Landlubber]

Adanmastor, you were told to run a separate wire from the battery and switch it via a relay......if you do not understand this, just say so mate and we can explain further......

[Adamastor]

My guess on the potentiometer, is, a variable voltage regulator.  I have heard of some police bikes having them.
Does it look like that is where the knob is located?

What year is your bike?  They changed over the years.

Hi!

It's a 1985 R65T (once had a fairing)..

Regards

[Adamastor]

Adanmastor, you were told to run a separate wire from the battery and switch it via a relay......if you do not understand this, just say so mate and we can explain further......

Oh, I should use the switch using the headlight power to power the switch... oh ok ... my confusion

[montmil]

Here's a link to a good relay technical article from the Airhead Beemers Club. Should be helpful to all.

http://www.airheads.org/content/view/159/98/

Monte
ABC #12411

[Adamastor]

Nice Link, Monte... that really explains switches

[Adamastor]

Today I took some photos of my electric section under the tank:



I discovered an empty plug (on the left) and have been testing it with a multimeter and discovered one of the pins is directly conected to the 12v source, while another one is only active when ignition key is on!
This looks like a perfect spot to connect my extra light with no need for a switch, right? I would just need to use a fuse (just to be safe)... Do you think the igniton "key on" power pin supplies enough power to the external light?



On this horizontal photo you can see what looks like a potentiometer (black box), what does it do, do you know?

REgards,

Sergio

[Bob_Roller]

Loosen the thumb screw on the black box, and you will find two 8 amp fuses inside .

That switched 12 vdc pin that you found on the unused electrical connector, check the voltage with the ignition switch in the 'ON' position, then move the headlight switch from low beam, to high beam, I think that there is power there only when the head light switch is in the low beam position, if that makes any difference to you .