Headlight bulb

My car's been tending to stall when I put the headlights on, so I investigated and found the earth terminal on the wiring connector that attaches to one of the bulbs was partly melted.

The earth appears to be OK, it has the same resistance to battery negative as the other side, gets the same voltage, so I suspected the bulb and changed it for a spare.

The bulb's earth terminal is a darker colour than the others, presumably through heat.

Is it heard-of for a bulb to go bad like this? That is, to develop (presumably) an internal resistance or something but still work.

Reply to
Mark W
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the hot spot (the connector) is the fault, higher resistance in the bulb will lower the power it takes and dim that bulb, not take more.

Reply to
Mrcheerful

I think that what you probably had is a short between the earth terminal and probably the dip beam terminal. As Mr Cheerful said, a high resistance in the bulb would mean it takes less power.

Reply to
malc

Thanks - after I changed the bulb the problem was still there - so next step is to make a new earth for the bulb.

Reply to
Mark W

Possibly. Disconnect the earth to that bulb and see if the fault goes away. It could be a short to ground on one of the supplies to the bulb.

Reply to
malc

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