Question about a newbie project

Discussion in 'The Projects Forum' started by GTPAddict, Mar 3, 2013.

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  1. GTPAddict

    Thread Starter New Member

    Mar 3, 2013
    Hello all. First off let em say I was blown away at the amount of information and posting in this forum. I've been looking around in here for any possible answers to my question for a couple hours before actually signing up. It's a bit overwhelming to say the least, especially for someone who's trying to do something that's a little over his head.

    The story...

    As do a lot of newer motorcycles, mine only runs one of the two headlights (left side) during normal operation. The second (right) headlight works as a high beam lamp, although it has a high and low beam filament. A popular modification is to wire the low beam filament to the dimmer switch and have a high/low beam right side headlight. This works beautifully since the dimmer switch is actually made to work this way (only one filament on at a time), the bike just wasn't wired for it. After doing this, both headlights are on all the time (so it doesn't look like you have a headlight out).

    The problem I ran in to is the charging system is not strong enough to support both headlights at idle speed for an extended period of time. I was stuck in traffic for over an hour one day. The bike stalled and the battery was not strong enough to restart the bike. This has only happened to me twice since I bought the bike 2 years ago, it charges just fine (close to 13 volts) over 3000 RPM (cruise RPM is usually closer to 6000).

    What I would like to do is build a device that will turn off the second headlight
    if the battery voltage drops below 12 volts. I plan on using a PIC 12F675 chip to control the headlight, monitor voltage, and delay the headlight coming back on for a period of time. Attached is a schematic I created base on my Google searches and what I found here. I have a PICKit1 Flash Starter kit I bought several years ago that I was going to use to program the chip (although I don't know how to do that yet either). I have not done anything else at this point.

    I am an automotive technician the specializes in drivability and electrical diagnostic, so I know a little about electronics, but designing circuits and programming chips is pretty much Greek to me. I hope to be able to do this, it would be a lot cooler then just installing a switch for when I get stuck in traffic :)

    Sorry for the long post guys and gals, and thanks in advance for any and all comments, help, and suggestions. If I can make this work, I want to make it available to my fellow motorcycle riders who may have found themselves in a similar situation.
  2. #12


    Nov 30, 2010
    Sorry. Wrong website. This one is not allowed to do automotive modifications. A moderator will be along in a little while to give you a list of automotive forums.
  3. Wendy


    Mar 24, 2008
    As has been mentioned, the owners of All About Circuits has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

    This thread is against the AAC forum rules, Chapter 6, as seen here:

    This can be found in our Terms of Service (ToS)

    Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

    Please try to understand the reasons behind this action, and feel free to browse and use the forums.

    You might find answers to your questions in one of these forums:

    Another good forum that shares many of the same membership is . Good luck.
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