Right side lights failed

Discussion in 'Airheads' started by MightyManfred, Feb 9, 2013.

  1. MightyManfred

    MightyManfred Been here awhile

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    I upgraded the turn signals on my '87 R80RT to use dual filament bulbs, using them as running lights. This was done 2 or 3 years ago and all was fine until a week ago. The turn signal idiot light now stays on; left turn signals & running lights work; right running lights and turn signals do not. Bulbs are fine - all work in the left side. Turn signal switch appears to function fine - the flasher is clicking the right side when no bulbs are in place. The front running lights share a common power as do the rear running lights. The stock front running/parking light and taillight (which provide the power to the auxiliary running lights).

    Would a bad ground do this? Is the flasher suspect - but would it keep the always-on running lights from working?
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  2. Rob Farmer

    Rob Farmer Long timer

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    I'm not sure about the side running lights but if it's just the indicator playing up My battery earth came adrift a few months ago and zapped the indicator relay giving a similar thing to yours. I replaced the blown transistors in mine for less than £1 so if you don't mind getting the soldering Iron out it can be a cheap fix.
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  3. MightyManfred

    MightyManfred Been here awhile

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    Thanks for your post, Rob. I enhanced the ground/earth from my battery a year ago, adding a second strap to the frame near the coils. The relay appears to be working fine - but no light on the right side.

    It's a bit dreary here today - will wait for slightly better weather and seek out ground wires from the front and see where it goes and what condition it's in.
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  4. disston

    disston ShadeTreeExpert

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    The only thing that is side specific would be the wiring or the switch. I suspect wiring. Can't say why exactly. Try switching something so the switch works backwards if you can and see if the problem follows the switch or the wires?
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  5. MightyManfred

    MightyManfred Been here awhile

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    That's a good idea. I will work on it maybe tomorrow, Wed for sure.

    Einstein was right - don't memorize what you know how to find in a book.
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  6. MightyManfred

    MightyManfred Been here awhile

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    Update.

    A.) Can't figure out how to get the plastic cover inside the turn signal switch off so I can see the wires and try swapping out left for right.

    B.) With both right side bulbs out, the flasher makes noise and the idiot light flashes off and on when I push the turn signal to the right.

    C.) Both running lights on each end of the bike (front and back) share a power line that comes off the parking light (front) or taillight (rear).

    D.) All lights on the front share a ground as do all lights in the rear.

    E.) I measure just under 12 volts on the running light tab inside the socket on the left side when ignition switch is on, less than 1 volt on the right side (front and back).

    I am more confused than when I started, yet I know it is something very simple. What that simple thing is escapes me at the moment.

    sigh
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  7. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    What did you do to upgrade the turn signals to add running lights? The "running light" part of the circuit should be separate from and independent of the turn signal circuit (except for a common ground).

    --Bill
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  8. MightyManfred

    MightyManfred Been here awhile

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    Bill,

    I enlarged the hole in the plastic a little and installed dual bulb sockets. Ran a power line from the tail light (rear) and parking light (front) to extra tab to provide power to the lower amp filament. Bottom line - it as you said: common ground, separate power.
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  9. disston

    disston ShadeTreeExpert

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    Dual filament bulbs use a different socket. You can't just add a wire to the single filament socket. Well? That's what it sounds like you said.

    And another thing you should know. BMWs are European standard machines. They use European bulbs in the turn signals and such. I forget the numbers at the moment but they are not the 1156 & 1157 bulbs we use in the West.
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  10. MightyManfred

    MightyManfred Been here awhile

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    No - I removed the standard socket, made the hole in the plastic a wee bit larger, inserted the dual tab socket and added the secondary power line for the running light filament. Using normal US dual filament bulbs.
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  11. MightyManfred

    MightyManfred Been here awhile

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    Simple. And easy to overlook. The common ground on each end of the bike terminates at each device. There ends the common part of the ground wire. When I installed the dual element sockets, I had to attached the ground wires to them differently than the stock sockets (I forget what the stock sockets look like so I cannot describe that difference). The ground wire attachment at both right side sockets had failed. Simple fatigue and an invisible open that I discovered on the front while simply poking around while trying to think.

    All lit up know - the bike, that is.

    Many thanks to those who volunteered some input here. :clap
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  12. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    The stock turn signal sockets do not have ground wires as such-- the ground to the chassis through the reflector/turn signal assy. Adding a two-contact socket to that reflector, you could either hope for good metal-to-metal contact (iffy) or solder a ground wire to the new socket shell (best).

    Glad it is solved... :clap

    --Bill
    #12
  13. MightyManfred

    MightyManfred Been here awhile

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    Methinks the RT signals do not ground directly - for sure not in front, where all is plastic.

    At any rate - great thanks to have this mystery put to bed!
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  14. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    Ah, I was thinking in /5-land, where the turnsignal housings and all are metal.

    "Nevermind"

    --Bill
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  15. MightyManfred

    MightyManfred Been here awhile

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    I know it's hard to keep all the details of all the airheads straight - look what it did to Snowbum!
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