dash "lights on" - cluster lamp and switch

Discussion in 'Mech Tech' started by pgtips, Nov 26, 2020.

  1. Hi,
    I'm rewiring my dash and was going through each bulb in the cluster I have got no lights on or main beam lamp lighting up.

    I had a electric fault which is the main reason for the rewire and these are the last 2 issues. The lights on my cluster illuminate but main beam and full beam lamp not working. Everything else is fine.

    Do the warning lamps for main and full beam route from the headlight switch (power) or does it route from elsewhere?
    I think it must be switch fed but I want to be sure what I should be checking first.

    I've not had engine running so possibly someone might tell me they don't light up unless running but I don't think that would be the case. I might have a faulty light switch?

    If anyone could throw me a pointer on this would be great I'm scratching my head a bit.

    PG
     
  2. mikedjames

    mikedjames Supporter

    Main beam and dipped headlights come on if the headlamp switch is pulled fully out, when you turn the ignition key to run position.
    Otherwise its sidelights only if the switch is either half or fully pulled out with the ignition off.
     
  3. thanks Mike,
    The bit I am looking at is the actual warning lamp on the cluster. Neither main or full beam illuminate which is what I want to solve.

    e.g no blue full beam warning lamp on the dash when I have full beam on, no main beam warning light when lights on.

    The lights to drive work ok
     
    Last edited: Nov 26, 2020
  4. I dont have a "lights-on" warning? Only the back lighting illuminates.

    The main beam not working could just need a better "earth" on the back of the cluster, try getting your hand behind and giving it a bit of a twist and wiggle to see if it wakes it up.
     
  5. The high beam warning light has a blue wire with white trace to the bulb on the back of the dash - the wire you've identified is for the backlighting (if i recall correctly) - if this isnt working give the knob a twiddle clockwise to increase the brightness.

    Are you using standard (not LED) bulbs?
     
  6. 77 Westy

    77 Westy Supporter

    The blue high/full beam warning light is supplied from fuse #5 (high beam left + indicator light).
     
    snotty likes this.
  7. Thank you, fuses are good but I have just stick some LEDs in ...

    I'll work back and remove anything not fed direct from the switch but I think that might be it, because everything else is working.
     
  8. matty

    matty Supporter

    If you have changed them to leds Are they the right way round .
     
  9. 77 Westy

    77 Westy Supporter

    Fuses Page 40.jpg
     
  10. What I'm going to do is put normal bulbs back in everything, like I say everything works bar the high beam/main beam dash light (green and blue) which is a normal bulb.

    It isn't fed from the light switch, there's a blue with green line and a blue with white dots wire which I assume run to fuse box. I'm not getting 12v at the bulb.

    My fuses are all ok but I'll double check.
     
  11. nicktuft

    nicktuft Supporter

    Not sure if I'm coming in right here but I do believe that the full head light beam warning light is fed from the fuse box after being switched from the dimmer relay..(j7) as per the Bentley wiring diagram.
    Hope that this useful.
     
    pgtips and 77 Westy like this.
  12. Zed

    Zed Gradually getting grumpier

    Late bays don't have a sidelights light, just the blue for full beam. The green is indicators?
     
  13. ^this
     
    nicktuft likes this.
  14. mikedjames

    mikedjames Supporter

    You cannot really use LEDs with the alternator warning light either - as one of the two failures does not light the light (either over or under voltage problems) depending on which way round the LED is inserted.
    Also it can cause problems with initial startup of the alternator if current cannot flow back properly from the ignition wiring to the alternator (LEDS drop quite a few volts even when "on")

    And my electronic flasher unit just squeals with a dimly lit LED on the dash if you use a LED for the indicator bulb in the dash too. .
     
  15. I don't have LEDs for battery light.
    I don't get any 'lights on' lamp on dash when I turn my lights on but my backlights work ok
    Everything works apart from cluster/dash lamps for the lights which are not fed directly from the light switch.
    I have main beam and high beam lamp on my US import bus.
    All LEDs swapped back, problem remains.
    Fuses are good. Disconnected battery then reconnected but no difference.
    I'm baffled
     
    Last edited: Nov 27, 2020

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