i'm stumped and hope that one of you guru types can help. my boy smashed the headlight on his cg125 in a low speed spill. i've fitted a complete headlight unit but gremlins have attacked. every light, indicator, horn etc works until i connect up the little pilot light. once this is connected, all the main lights go out, including the instrument lights (indicators, horn, and dash warning lights still work fine). pull the connectors apart for the pilot light and everything else works again. any ideas please?

  • Welcome to Motor Vehicle Maintenance & Repair! "Pilot light" ... not sure what you're talking about? I'd think you probably have something wired backwards in whatever you fixed, but don't know. If you have any other information, it would surely help us to diagnose. Jul 15 '18 at 20:37
  • inside the headlamp unit there is the main light (dip and main beam), there is also a small 4w pilot bulb (sidelight on a car) which should illuminate with the dash lights on the first position of the switch. there's only two wires on it, colour coded, but when it's connected the other lights, including dash lights will not illuminate.
    – rob
    Jul 15 '18 at 21:12
  • Trace your pilot light wiring back from where it is to where it gets power/ground. I'll bet you've got a bad ground (or one not connected) which allows the power to go through the lights, but when you connect this particular light (for some reason), it interrupts the ground, which shuts all of the other lights down. Jul 15 '18 at 21:28
  • Test the pilot light bulb itself - a faulty bulb can cause issues...
    – Solar Mike
    Jul 15 '18 at 21:29
  • i've had the wires to the holder, held across the battery terminals and the bulb illuminates just fine. pilot light earths through the same 4way connector as the headlamp, and the dash lights, and these work fine until the piot light is plugged in. i've tried removing everything from the connector except the pilot light and it still won't play ball. the pilot light draws it's power from the same connector as the tail light and the dash light, and again, both of these work fine. it's a bit of a head scratcher this one.
    – rob
    Jul 15 '18 at 21:43

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