Headlight, neutral indicator, and brake indicator not working

[TwoFitty]

I am very new to the electrical components of my xs and I am not sure what could have caused this. My headlight stopped working yesterday on my 77 xs650. Then today the neutral indicator and brake light indicator stopped working. I doubt that all of the lights have burned out so I assume it has to be wiring somewhere, also I can see both filaments in the headlight and they are not broken. The bike is running great and the brake light, turn signals, horn, and head light indicator work fine. I am not sure where to start. Any help would be appreciated. Thanks.

 

[retiredgentleman]

Look in the "Tech" section...............wiring diagrams. There is a diagram for the 1977 year.

Buy a VOM if you don't have one. Learn to read wiring diagrams.................yes they are hard to read. If you plan to own old motorcycles, you need to know how to follow wiring diagrams.

A good guess is the problem is inside the head light bucket, but could be other locations also.

 

[XSLeo]

Well the first thing I would do is start at one end of the bike and work to the other. Checking every connection for clean and tight. A dab of dialectric grease will help keep them clean. This includes switches too. Pay particular attention to grounds.
77 was 36 years ago, how long are bulbs supposed to last? As you are checking the connections, check the bulbs just in case. Don't just look. I use my meter or one of the extra bulb sockets and test by touching the leads to a battery.
Leo

 

[TwoFitty]

So I hooked the headlamp up to the battery and it works just fine. I have voltage across the hookups for the lamp but when I hook the lamp up the voltage drops to zero. I'm at a loss... My guess would be the light has a short but it works when connected to the battery.

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[retiredgentleman]

So I hooked the headlamp up to the battery and it works just fine. I have voltage across the hookups for the lamp but when I hook the lamp up the voltage drops to zero. I'm at a loss... My guess would be the light has a short but it works when connected to the battery.

Posted via Mobile

The light does not have a short. The fact that the voltage drops to zero indicates that there is high resistance in the circuit that feeds the light. That high resistance is dropping all the voltage. That could be the head light switch or the high/low switch or corroded bullet connectors, etc. Use a VOM to measure the resistance.

 

[XSLeo]

I agree with RG. Check all the connections in the circuit. A lose or corroded conec tion can carry enough power to show a voltage but not carry enough current to light the headlight.
That's why I suggested you clean and tighten every connection in your wiring. This often fixes many electrical problems before they become problems.
Leo

 

[5twins]

Yes, 30+ year old bikes need a little 'lectric lovin', lol. Don't go through the entire system as you've been told to do and new problems will be cropping up quite regularly. Come to think of it, since you've signed up here recently, you seem to be checking in every few days with a new problem, imagine that.