headlight not working

[thunder7777777]

my head light and tac/speedo lights don't come on

when I jump the relay, they work, but then the battery dies,

I tried running a- and + wire to the battery from the headlight, with a toggle switch, but when the light is on the battery dies, with the light off the battery charges fine.

I put in a new relay, same thing,

is my charging system going to ground, when the light is on

help needed, thanks

[79XS11F]

The voltage regulator might be toast and sending all charge voltage to ground. Test it. Anytime there is a mystery electoral issue start by confirming the regulator and other key components. If they all check out then start checking circuit by circuit. To find electoral issues you MUST approach the issue in a organized and methodical fashion.
Rob

[thunder7777777]

thanks Rob,

how does one check the regulator, this is all new to me,

what if I was to by pass the RLU,

[TopCatGr58]

Hey THunder,

The reason Rob stated to check the charging system FIRST, is because when it's NOT charging, then the symptoms you are experiencing are common! The headlight relay latches to turn on the headlight WHEN it receives a voltage from the ALT, but if the ALT isn't charging, then no signal, no headlight relay latch, no headlight!

The Tach also receives a signal from the ALT for it to work, not from the coils, so again, when ALT not charging, no pulse signal to tach, no tach readout!

There are tech tips that will direct you to how to check your charging system. Remove/separate all connectors linked with the charging system and clean....including the ones behind the fuse panel that come from the ALT!
T.C.

[skids]

If this is an xs11, turn on the key and hold something iron against the right case cover. If your VR is trying to charge a weak battery, there will be a strong magnetic field. A bad battery can be so weak that the headlight can kill the engine because it needs like 10.2 volts to the black box just to create ignuition spark. The key switch turns on the blue wire (runners) and the brown wire (fuses), bu connecting the red (supply hot) and you may need to clean it. See if wiggling the key has any affect, or jumper those wires together and see if the lights come on (headlight will need the bike running), but make sure the engine is at least 2000 rpms to "carry the load."

Originally posted by thunder7777777
thanks Rob,

how does one check the regulator, this is all new to me,

what if I was to by pass the RLU,