Breva 1100 Headlight/Dash wiring

[LeakyLogic]

First let me say I am by no means an expert on wiring. I suck at it.

However, my Breva 1100 currently has aux driving lights instead of using high beams. The previous owner did this because he found the high beams useless. Given the history of problems with dashes going bad, I was wondering if changing the setup to include the high beams might draw too much power and contribute to shorter life of the dash and handlebar switch from excessive resistance/draw.

Researching how the headlights work lead me to this hypothesis. It seems the handlebar light switch is not connected to a relay and full power flows to the headlight. It also seems that the dash contributes to the operation of the headlights, signals, brake lights if I recall correctly. I based this assumption off the forums describing dash failures and failures of headlight, signals, etc...

So if I have both driving lights and high beam on and all of this power is running through both the handlebar switch and dash can this have a negative effect n the life of these components

Will wiring a relay to operate the aux lights and using the handlebar switch, that transmits full power to headlights, fry the relay for aux lights?

How do you wire both the aux lights and high beam to a relay without harming the new relay and impacting the dash?

Perhaps I'll just leave it alone. Feel free to ponder.

[Bisbonian]

I don't know the real answer.
But I know that if I wanted to power my auxiliary lights from the standard high beam switch then I'd put a relay into the circuit and just use the bike's high beam wire to trigger that relay rather than put the auxiliary lights tapped all the way in and running off the same wire as the normal high beam.

[guzzisteve]

No relay, really.  Wiring Diagram #4 is lights relay, did you not read it. Wires they use are too tiny for full current.

[LeakyLogic]

Thank you for helping me understand. I will have to get familiar with the wiring diagrams and not take some of the info I find online as gospel.

[Moto]

No relay, really.  Wiring Diagram #4 is lights relay, did you not read it. Wires they use are too tiny for full current.

Executive Summary

There is no high amperage headlamp flow through the ECU dash, but there is probably such a current through the left handlebar switch of the Breva 1100 on high beam. Your solution should be to connect both your head lamp and the auxiliary lamps to the output terminal of a suitable, high-amperage relay, triggered from the disconnected head lamp high beam wire of the original circuit.

Details

The light relay is activated by a low amperage circuit (connector terminals 1 and 2) that the ECU dash connects to ground when the engine starts. When the relay closes, terminal 5 becomes hot, feeding a  black wire to the headlamp and to the left handlebar switch. The wire to the headlamp is the high-current feed to the low beam filament.

Whether the circuit completed from the black wire through the left handlebar switch and then through the white wire to the high beam filament is high current, or merely a low current trigger, is unclear: there is also a continuation of the black wire circuit shown going directly from the low beam to the high beam bulb(!). There must be either an error in the wiring diagram or a relay in the headlamp that is not shown.

It is interesting that the wiring diagram for the Breva's sexier brother, the Griso 1100, is different, even though the handlebar lighting switch is diagrammed as the same. In the Griso, both the low and high beam high amperage circuits go from the light relay through the left handlebar switch.

So, for the Griso there is high amperage going through the handlebar switch for both high and low beam. For the Breva, there is no current through the handlebar switch for low beam, and either a low or high amperage current for high beam. My guess is that it is high amperage.

I don't quite understand where your existing relay for the auxiliary lamps is, but if you want to wire one that will feed high current to the auxiliaries while leaving your high beam circuit as it was (and operating in parallel with the auxiliaries), obtain a four-terminal normally open 12v relay and do this:

1. Connect the white wire at the high beam bulb to terminal 86 of the relay.

2. Connect terminal 85 to ground. That circuit is the trigger.

3. Connect terminal 30 to the battery, via an appropriate fuse.

4. Connect terminal 87 to the auxiliary lamp(s).

You can find the wiring setup I just described here:

http://www.12voltplanet.co.uk/relay-guide.html

It's under the heading, "1. Adding driving lights that come on with the headlight main beam."

Actually getting around to your question: "How do you wire both the aux lights and high beam to a relay without harming the new relay and impacting the dash?" -- If the high beam was disconnected by the PO and you complete the relay wiring as described, you can also connect the high beam to terminal 87. You should check your relay's rated amperage: it should be greater than the sum of the amps drawn by the headlight and the two auxiliary lamps. Your wire from the battery should be 14 gauge, I'd say. Many would recommend 12 gauge. This setup has the advantage of making it completely clear that no high amperage will be going through the handlebar switch (if it ever did). Your dash will be completely unaffected.

Hope this helps. Sorry to have written so much.

Moto

[LeakyLogic]

Your feedback helped me understand and may provide me with the required confidence to tackle some type of an improvement. Food for thought and I enjoyed the explanation, thorough and without ambiguity.