1981 XS1100SH headlamp wont work

[elpasobound]

hello everyone,

i have not posted in a long time, but I NEED HELP.

I have a 1981 XS1100SH. Headlight will not work.

Bulb looks fine.

TM says it is either headlight relay or headlight reserve lighting system. Both are located under the gas tank

I called Yamaha dealer and the headlight reserve lighting system is DISCONTINUED. Sales person could not identify the relay.

How can I find these things, or make a workaround to get headlamp working??

I have very little electical repair experience. Would really appreciate some help.

Tim Billington
XS1100SH, 1981
El Paso, TX

[Snow]

I *believe* you can just bypass the HRU - the only thing it does is cut the headlight off when the bike is not actually running if I understand it correctly.

Also, if you determine that it is the HRU, I'm sure Andreas probably has one lying around. It'd be much better to have a working HRU in place than to keep it bypassed.

[skids]

I am a fan of bypassing the sucker! Here is how (pick that link):

http://home.comcast.net/~sidhansen/motorcycles.htm

[HobbyMan]

Dumb question, but did you check the fuse? Actually test it, don't just look at it. The glass ones sometimes burn at the caps where you don't see. Test for voltage at the relay. None of my bikes has ever had a reserve lighting unit go out. Like
I said, check for power starting at the fuse panel and work your way up. At the relay, you can trigger it with a paper clip and then test further on up the circuit.

[TopCatGr58]

Just a side note,

Is your tach working? Sometimes the charging system goes, and the headlight will not LATCH the relay cause it doesn't sense any charging current thru it, and this will also affect the Tach, so it won't read, or jumps a lot. Have you checked your voltage across the battery with it running at 2500 rpm or so and see if you are getting close to 14+ volts? IF only 12 volts or less, then it's not charging, the headlight is then the last of your trouble shooting!
T.C.

[fredintoon]

simplify

Hi Tim,
if all else fails, there's a simplified wiring diagram on this very list. It bypasses everything.
http://www.xs11.com/forum/showthread...wiring+diagram
Fred Hill, S'toon.

[dale_1]

break out an ohm meter

Multimeters are the best troubleshooting items you have out there.

Just turn your multimeter over to OHMS / Resistance / or the "Omega" symbol and give it a read.

Most have the audible alert. I use that when checking bulbs for continuity or fuses. I never go by the bulb or fuse looking good. Been "burned" too many times by that. (weak pun couldn't help myself sorry)

Good luck and keep digging

[HobbyMan]

or you could go crazy and measure in Mho. The reciprocal of an ohm. Not many people do that except me that I know.