I replaced the standard bulb with a EuroDesizns H4 bulb. This bulb, according to Sylvania draws no more current than the standard bulb (55-60). I searched the forum before I bought the bulb and noticed that quite a few of you had already used the Sylvania H4 bulb.

The next day I went for a long drive and notice my headlight wasn't working later in the day. I took it apart and the ground wire lug in the phenolic connector is completed melted out. The strange part is that the wires are fine, hence the current draw could not have been the cause. But it doesn't seem it was excess heat either since only the ground wire lug melted out of the plug.

I have to cut and replace the entire connector, it is fried.......

Anyone hear of anything like this?

 

If the ground was not a tight connection, there could have been heat generated in that connection only. Don't forget, the ground has to carry the full load, same as the power lead. Clean, tight connections are a MUST for any current to pass.

 

thanks Rick, I thought of the same thing, the only issue is nothing changed except the light bulb. I suppose, in dis-assembling the light that the shell jiggled some, just enough to disturb the ground through the forks etc. Or, even more bizarre, the ground lug mating connector had some dirt in it, just enough to drop some voltage across it........

Apparently I didn't see the bullseye on my back and Mister Murphy got me..........

I am going to replace the connector and put an ampmeter on it before I re-assemble....

 

Don't know from bikes, but in cars/trucks, its always the connector that melts, not the wires until after the connector has smoked.

I'd say you are drawing higher current than it was designed for and the bulb may have been mislabeled.
You could also have a bad connection and be delivering lower than optimal voltage causing a higher amperage draw which would create more heat.