Trunk light without a switch?


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Christian SU
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Trunk light without a switch?

Post by Christian SU »



I would like to install light into my trunk and into the sattlebags of my SC47 (built in 2009). There are already countless installation suggestions for this, but they all require a switch to change the light from off to on.
The locks are equipped with a switch which reports if the door is open or closed. This is shown in the system display. My question is, whether i could tap (without destroying the ECU) this signal (eventually via a relay) to switch my lights on and off?


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k2mpw
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Re: Trunk light without a switch?

Post by k2mpw »

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Christian SU
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Re: Trunk light without a switch?

Post by Christian SU »

@k2mpw
This is also an elegant solution. But at the end: a reed switch is a switch.
Why not using the installed lock switches?
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k2mpw
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Re: Trunk light without a switch?

Post by k2mpw »

It came down to taking the mechanics apart or adding the red switch. The trunk switch is finicky enough without me farting around with it.
To use the oem logic switches, I would suggest isolating them from whatever LED load you want to use.
Digging into the machanics, I'm sure its gonna be a ground or a hot when the lids are open.
That signal could be used with a optically isolated relay board (Ebay <$5) to control whatever you want as long as the load is within the limits of the relay.
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Christian SU
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Re: Trunk light without a switch?

Post by Christian SU »

k2mpw wrote: Tue Apr 13, 2021 6:52 am...could be used with a optically isolated relay board...
That's a great idea. I'll play with that.
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Rambozo
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Re: Trunk light without a switch?

Post by Rambozo »

There are also purpose made trunk lights with a built in mercury switch so they go on when the lid is opened and only require a power lead. Some are battery powered so no wiring required. Of course these days the mercury switch has been replaced with an accelerometer or motion sensor and a micro controller, but the result is the same. And with LEDs the batteries will last quite a long time.
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k2mpw
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Re: Trunk light without a switch?

Post by k2mpw »

Taking the inside cover off my 2012, I see the switches and a wire but access to it means pulling off the lower trunk covers.
Trunk switches go through C45 in the lower trunk then C31 under the seat on the right side. Its a 14 pin Grey connector with a Br/R wire.

The saddle bags are the same color wire but they don't go through either of those connectors. That would have been perfect...
Accessing their switches can supposedly be done inside each SB.

The switches are to ground. The job is to figure out if when the doors are closed, they too are closed and shunt to ground.
superg
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Re: Trunk light without a switch?

Post by superg »

I make mine light working on the switch that is already in the trunk.
That switch is switching the nul/earth wire, so you need a plus. In the trunk i had a wire with constant 12v and in the sadle bag I get power from the tail light so that only works when the bike is on.

you need tinny hands, but it can be done.
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GoldWingrGreg
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Re: Trunk light without a switch?

Post by GoldWingrGreg »

I have a Hondaline trunk light. All though it is not the greatest solution, and offers no light for the saddle bags, it extremely reliable and only lights when the trunk is open.


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