Lost my headlight and tach/speedo lights

[johnstewart]

Hello all.

1979 XS1100SF

The other day I was on a long ride and noticed near the end I had no headlight. I also seem to be missing my tach/speedo and high beam indicator lights. All other lights seem to work fine (oil pressure, signals, brake).

The fuses are good (and it's a replacement auto-style fusebox, not original, so solid).

The headlight plug didn't appear to be getting any voltage (so the lamp itself appears to be fine).

I've got a parts bike, and have swapped out 3 different boxes under the seat and tank, including the reserve unit. Still the same deal... however, I'm not sure I've replaced what I really should (what could affect all of this?)

I'm guessing there must be a loose wire someplace (or is it something else?).

Please help; I'm desperate to ride! I hate caging it. =)

Any suggestions?

thanks!!

johnS

[BLUEJEEPLAB]

Fuses are good, so that eliminates a short. Try a continuity Check between the Headlight Plug and the fuse block. You should have a few ohms of resistance at most if the wire is good. Do you have voltage at the fuse block?

[JWSanders]

You might want to check to make sure your alternator is putting out voltage.

Rev the engine to 5000 while metering the battery. Should get just over 14 volts.

If the alternator is not outputting, the headlights will not work, and the tach will be dead, as well.

[TopCatGr58]

To Followup on what JW Sanders said, IF it's not charging, then a quick swap out of the Reg/Rect with one from your parts bike "May" provide a fix! Check the charging effect after you swap out the R/R to be sure it's working. Also check and clean the connectors behind the fuseblock where the ALT plugs into the harness...the white wires!!
T.C.

[johnstewart]

Awesome; thanks for the suggestions. This is my weekend mission (too damn busy tonight), so at least *one* more day of caging it.

Thank you!

[BLUEJEEPLAB]

May be even as simple as Cleaning the battery terminals. I was having a problem early in the spring and cleaned the terminals and now run at a minimum of 12.5 volts. Up to 14 from the charging system at 3500 and above. How do I know? I installed a voltmeter in the fairing, nice little instrument to have on an XS.

[johnstewart]

Alas, the XS11 couldn't be my top priority this weekend (I had a garage and two decks to paint), but I just did spend a few minutes with it before the sun went down.

The alternator is definitely good. Battery shows a solid 13V before starting, and 14V when revving up to 4-5k.

BLUEJEEPLAB - you suggested a resistance check between the headlight plug and fuse block. Looking at the wiring diagram, it looks like there is no direct connect between the fuse block and headlight; which wires should I be checking?

I did find connectivity between the reverse lighting unit and the yellow wire on the headlight (with .4 ohms).

I know the previous owner did some dumb crap with this bike. I think a full fairing used to be on it, and then was removed and put back together not-quite-right.

I know when I bought it, the high and low beams were reversed, and I had to swap the wires (so coming out of the harness it goes from white to yellow and vice versa at the splices). Not sure where the funkiness comes in...

And I also did connectivity testing from the headlight connectors to ground. Dunno if this is significant, but only the middle headlight connector was *not* at ground.

I still need to spend an afternoon with the wiring diagram, I guess. If only I could grok what could take out the headlight *and* the tach/speedo lights...

thanks

[johnstewart]

Well, did a little more diagnostic work, but I'm still stumped as to where I should be looking.

I scanned in the wiring diagram and color coded it to try and find some commonality in what's messed up. I see none.

Speedo lights? No
Tach lights? No
Neutral light? Yes
Hi beam indicator? No
Signal L? Yes
Signal R? Yes
Fuel low indicator? Yes

http://www.johnstewart.com/pics/cycl...ring_color.jpg

[yamarider]

John, I have the same issue with my '79. The difference is that I have a fairing, so I am able to do a few different things. What I did was direct-wire the headlight through a simple on-off switch that I installed on the fairing. Problem solved. As for your instrument lights, do you have the squre instruments? I took a flat piece of plastic that was sturdy yet thin enough to wedge between the top of the instrument housings and the turn signal indicators and custom-designed an illumination lighting system that attached to the underneath side of the plastic, using small auto lighting accent lights. The lights are attached with simple double-sided sticky tabs and I spliced them into a hot wire that is on whenever the key is on. So basically, the piece of plastic is sticking up at an angle and the little lights are shinging down on the faces of the instruments. The whole thing works perfectly. If you are having a hard time visualising what I am describing, I could email you some pics.

[TopCatGr58]

Hey John,

I would look very closely at the RLU(Reserve Lighting Unit)!! Both the SPeedo lights tap off of the Blue/Black to blue wires, and the Headlight also come from it (Yellow). There's a tech tip on how to bypass the RLU, with an updated link to Sid's web page which has more XS11 specific RLU bypass info!!
T.C.

[johnstewart]

I see this listed under TechTips for RLU, in the offsite section, but it's gone:

http://www.sonic.net/~blaineh/motorcycles.html

Anyone have a local copy?

Edit: nevermind, found this:

http://web.archive.org/web/200304190...eliteunit.html


Will at least give this a shot!

[TopCatGr58]

Hey John,

Here's the Skids Link:Bypass RLU It was at the bottom of the tech tips from the MAIN FORUM PAGE, Mods, Electrical, not necessarily from the link on the LEFT COLUMN.
T.C.

[johnstewart]

Originally posted by TopCatGr58
Hey John,

I would look very closely at the RLU(Reserve Lighting Unit)!! Both the SPeedo lights tap off of the Blue/Black to blue wires, and the Headlight also come from it (Yellow). There's a tech tip on how to bypass the RLU, with an updated link to Sid's web page which has more XS11 specific RLU bypass info!!
T.C.

No joy. I used some aluminum foil to put a temporary bypass in place; same behaviour.

I notice that the RLU doesn't seem to directly connect to the tach lights, which are also out.

My, this is frustrating! If it's not an electrical problem on one of these bikes, then it's definitely an electrical problem. =)

Desperate times; I'm gonna have to get my CX500 running again whilst the XS11 is out of service.

Problem is, if I took this to the mechanic, I can only speculate how many hours they might spend trying to diagnose. =(

[JWSanders]

I know you said you swapped them out, but this is now pointing to the headlight relay as being the culprit.

Read this post, it may help:

http://www.xs11.com/forum/showthread...eadlight+relay

[johnstewart]

Originally posted by JWSanders
I know you said you swapped them out, but this is now pointing to the headlight relay as being the culprit.

Read this post, it may help:

http://www.xs11.com/forum/showthread...eadlight+relay

Sounds like the same thing; I'm betting the relay is good but one of the wires is not.

thank you!