Headlight Help!

Just noticed coming home at night this week that neither my HI or LO headlight beams were working. Got 2 H7s yesterday and started the process of putting them in today. Disconnected both of the connectors (HI and LO) going to the two headlights. However, when checking the voltage at each connectors - the reading was zero - regardless of the position of the handlebar HI-LO switch - so thinking now that the bulbs have not burned out.

Since neither the HI or LO have voltage - am thinking that there is no voltage going to the handlebar switch - if that is the problem, what could be the cause? Is there some component failure? How would you suggest that I troubleshoot this matter? Any thoughts are appreciated. I do have a Honda Service Manual but am going blind trying to trace the electrical diagram and not sure that I can read what is going on anyway.

Power to the lights also goes through the the starter button (disconnects the power when pressed) you may want to check that out too.

Relay or fuse

micbusathens wrote:

Relay or fuse

The 15amp headlight fuse is OK.

Could failure of the Low Beam Relay impact BOTH HI and LO beam?

Dimond,

Low and high beam uses the same relay - that is probably your common demoninator.

Cheers,

RArch wrote:

Power to the lights also goes through the the starter button (disconnects the power when pressed) you may want to check that out too.

Indeed it was the starter switch. Turns out that the soldered connection where the 'hot line' wire that powers the headlights failed (broke off) at the inside area of the starter switch. This explains why both HI and LO beams failed at the same time and when this happens to you at night it sure grabs your attention. However, now that the connection has been soldered back together, ALL IS WELL!

Thanks to all for your input!

Makes you wonder if the solder melted due to a lot of current passing through (causing heat), must have a bad joint from the beginning...

Glad its sorted

RArch wrote:

Makes you wonder if the solder melted due to a lot of current passing through (causing heat), must have a bad joint from the beginning...

The break was a migty small solder area - so it may have overheated - hard to say. I am guessing it was either a very small solder cross section that either overheated or was mechanically stressed. The resolder was a much bigger area - so hoping it holds!

Nice to know the fault was diagnosed, investigated and fault found.

Thanks for the follow up Dimond.