Lost my headlight/gauge lights!

[TopCatGr58]

Hey there folks,

Okay, it had been a few weeks since I had ridden Godzilla, and I needed to get to the local HF for some 24" tire irons, and to take an eMachines desktop minitower back to George/GloweVa, and had already done the weekly shopping, so I decided to load up the bike and take a little trip. The weather was nice and clear, upper 80s, but minimal humidity, a bit breezy, but that's okay.

I went thru the downtown tunnel and noticed that my gauge lights were working along with the reflection of the headlight off of the car infront of me.
Got to George's, but he wasn't home, but he had left his laundry room door open, so I just set the 'puter in there out of site, and then left for HF on my return trip. Got the 3 tire irons, and a cheap SAE tap/die set for a little project I'll post in the next day AFTER I get it done.

Then rode back thru the downtown tunnel, and looked down and noticed that I couldn't see my gauge lights nor a reflection of my headlight off of the car infront of me....my turn signals still worked. When I got to the other store for a few items I had forgotten, I verified that the tail lights and brake lights still worked! It was still sunny daylight, so I just rode the few miles back home. BTW, the tachometer was still working, and my voltmeter was still showing 13-14 volts depending on rpms....I have that mini-auto-race 1 wire alt mod.

Arrived home, and shut it off, pulled the headlight fuse, still intact!

So....I think I'm looking at the headlight relay....since my tach is still working, I know I've got the latching signal from the tap I put on the mini-race alt to that yellow wire in the harness behind the fusepanel..so that it would have the diode provide a simulated DC type latching voltage to the relay.

I will be pulling the tank off, along with the valve cover, so I'll be able to remove the relay and put a jumper on it for the diagnostic step, and if that works, then I'll probably figure out a way to put a SWITCH on the headlight circuit so that I can shut it off during starting, I don't really care about having the OEM relay, just another fault point to eliminate. I also don't use the self cancelling feature, and I have an HID projector mod as well, so I don't need the reserve lighting unit either. I just don't know about removing the RLU...but now that I think about it, I may have already bypassed it!?

T.C.

[jetmechmarty]

So....I think I'm looking at the headlight relay....since my tach is still working, I know I've got the latching signal from the tap I put on the mini-race alt to that yellow wire in the harness behind the fusepanel..so that it would have the diode provide a simulated DC type latching voltage to the relay.

TC,

There's a diode in the harness under the tank. It's in the white wire between the regulator rectifier and the headlight relay. Is that the diode you're talking about? I think you'll find that the diode is open. Of coarse, I say this without full knowledge of your modifications.

[Big Beadle]

I have been having the same issues, On startup the bike fires up but I have no tach or headlight....After a min or two everything will spring to life and work as normal. There has been times were ill loose both when riding down the road, A simple restart will usally bring both back to life... It sound like the same issue TC is having..Any Ideas?

[jetmechmarty]

I have been having the same issues, On startup the bike fires up but I have no tach or headlight....After a min or two everything will spring to life and work as normal. There has been times were ill loose both when riding down the road, A simple restart will usually bring both back to life... It sound like the same issue TC is having..Any Ideas?

Since your's will reset, I would be suspicious of a faulty headlight relay or poor connection in that circuit. TC says he may have bypassed the relay leaving the diode. You get a reset because the relay is energized by a signal from the ac generator and regulator/rectifier when you start the bike.

[BA80]

The diode went bad on Okie the other day too. I just bypassed the headlight relay.

I might go in and fix it this winter but having the light come on just with the key ain't that bad. Unless you have a bad battery it doesn't make a difference,

[jetmechmarty]

When the diode goes bad, the harness has to come apart to some degree in order to fix it. If the lights are coming on with a reset, I don't think the diode is the issue.

[TopCatGr58]

Well,

Not to hijack my own thread, but a curious turn of events occured today.

I went out to start to work on the bike, take the saddlebags, seat, and stuff to be able to get the tank off, and I happened to look down at the rear wheel, and saw an UGLY sight!



SO....my plans changed a bit, instead of chasing down the electrical problem, I had to investigate the oil bath and final drive status!

Got the rear end disassembled, the wheel off, and looking inside the final drive I saw this:



SO...with all of the 90 wt hypoid gear oil all over the place, looks like the internal seal finally blew! SO...fortunately I had a spare from another 81H partszer, pulled it out and checked it out, still had nice yellow oil leak from the vent when I turned it slighly upside down! Just needed a lot of cleaning, and swapping out of the filler plug bolt, along with draining and refilling of course.

However, the shock mount shaft didn't look right....it was sticking out a lot farther than my special's...and was tilted?? So...I took a gentle hammer to it and it moved more towards the perpendicular. SO...I wondered if they were PRESSED IN, or what? I didn't take the time to look at the parts fiche, just grabbed a small pipe wrench, stuck the FD in a vice, and started turning the mounting bolt, and it spun, and finally came out. SO it IS threaded into the FD! I then proceeded to remove the one from my special because it wasn't as rusted and such. Cleaned it up nicely with a wire wheel, and then applied some "BLUE" locktite to the threaded end, and put it into the replacement FD and tightened it back down till it seated!



SO...I just got back from Wallyworld, and sprayed painted it glossy black, will let it cure overnight under the 1000 watt shop light and fan, and then I should be able to reinstall it tomorrow fairly quickly, and then get back to the electrical situation!

When I went for my ride yesterday, I didn't check the rear tire pressure, it has a very slow leak, so I just took it easy, didn't take the corners anywhere as aggressively as I usually do....go thing...with that hypoid gear oil slinging off the left side of the tire, it could have been a nasty fall! Luck of the Irish I guess!

T.C.

[BA80]

Did you check that left rear wheel bearing TC? If that bearing is bad that might be why the seal went out.

[3Phase]

T.C., Beadle,

There's probably a bunch of old electricity clogging up the wires, the Tach and the Headlight relay. You just need to ride more often and flush out the old sticky electricity!



Alright! Alright! <dodging cow pies>

T.C., the Headlight relay/diode and the Tach on Godzilla were on different White wires before you made the alternator mod. The only Yellow wire behind the Fuse block would have been the unused one from the old OEM Stator and you got rid of that. Did you add a Yellow wire from the new alternator for the Headlight relay and/or the Tach?

You got LUCKY with that final drive shock mount bolt! The guys on the UK site went through seven levels of heck and darn'ation trying to remove that bolt to see if it was threaded or pressed. It's not listed as a separate part because it's LocTited in the housing and it was only sold as part of a new Final Drive.


....

Beadle, you have a '79 Special in your sig' and it's wired differently (a lot differently!) than T.C.'s Godzilla.


The Headlight relay on all '78/'79 XS11s uses the Yellow center-tap wire from the alternator.

The Tachometer runs off one of the White wires from the alternator.

Unless the Headlight relay latching coil has a short circuit that kills the alternator it shouldn't affect the Tach.

Since both of them are are giving you a . . . delay but they both eventually work you probably have a dirty or bad alternator connector. The alternator connector is a 4-pole connector and it's behind the Fuse block with three White wires and one Yellow wire.

Check it out!


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[BA80]

The dash lights and the headlight work off the headlight relay. I just went through the diode failure 2 days ago. The dash lights (speedo and tach)and headlight wouldn't work until I bypassed the relay on my SG.

[TopCatGr58]

Did you check that left rear wheel bearing TC? If that bearing is bad that might be why the seal went out.

Hey Greg,

I was rushing to get to dinner, so I forgot to mention that, I did check the bearing while I was cleaning the wheel, it's still very nice and snug/smooth!
The FD has an estimated 75k on it, and when I drained it, I thought I saw a bunch of fine black particles, not METAL, so it was probably the seal breaking down.

Scott, I can't remember now if the wire was white or yellow, but thought it was yellow, an extra one separate from the 3 old ALT circuit....I do remember there being an extra wire, and I ran the new mini-alt tap to that wire so it would go to the tach and the headlight relay thru the diode.

I remember you posting about the 81's using a different style relay with a different voltage requirement. Will I be able to run a test jump from the battery to that yellow/latch wire with the key on and see if the relay catches to help further confirm that the relay is bad first before bypassing it? I don't really want to go cutting into the main harness and unwrap it and such!

Also, couldn't I wire in a regular type relay and use a tap from the main 1 wire charging wire to act as the latching signal instead of a feed from the tapped alt phase, thereby eliminating the need for a diode? Oh...I see the problem...the 1 red thick charging wire is connected to the (+) terminal of the battery, so it's hot all the time...DOH! Okay, then I can just wire in a switch and a relay that way. I've done it for my horns.

T.C.

[BA80]

Hey Greg,

I did check the bearing while I was cleaning the wheel, it's still very nice and snug/smooth!
T.C.

Maybe a silly question but did you actually pull the spacer, seal, and inner race out to check it?

[TopCatGr58]

Maybe a silly question but did you actually pull the spacer, seal, and inner race out to check it?

Hey Greg,

It's a sealed bearing design, so nope, I just stuck my finger into it, and pushed and rotated it , and could feel it spin smoothly, and it didn't feel loose/wobbly at all. I've got a new replacement one from James England if needed, but this one still feels great. Surprisingly the new one doesn't have any seal on it, so I know I would need to pack it full of grease before installing. I know I read about being able to pull the seal, but I'm afraid to! I would think if the bearings were getting chewed up that I would be able to feel the roughness when I spin the inner race while applying pressure towards the rollers. Do you think I should risk damaging the seal to pull it out, and then repack it with fresh grease anyways. I understand and realize now that the seal doesn't keep the bearing together that it's merely a dust/dirt type of protection device as well as to try to keep the grease IN the bearing and not let it get flung out with use.

T.C.

Okay, showing my ignorance here since I have never had to take the left side bearing out. I just reviewed the replace rear wheel bearings tip, and realized that I was only feeling the outer spacer and seal, not the INNER bearing! I'll play with it in the morning and verify that the bearing is in good shape. If not, I have one I can put in, but will need to get the right side bearing, but that's an easier task than the left one!

[BA80]

The seal and that short spacer are separate from the bearing, it is not a sealed unit. Once the seal and the spacer are removed the inner race will pull out and expose the rollers.

Here is a pic of one taken apart.....



The small spacer (top right) has a lip on it behind the seal that keeps it from just falling out but gently prying it out of the seal won't harm the seal. The seal comes out quite easily and then the inner race (on the edge of the wheel center) will just slide up out of the rollers.

Yes, you should clean and grease the rollers as necessary. I don't like using solvents on bearings simply because it's impossible to get it all out and will break down the fresh grease you put in there. If the bearing is still good the grease will be too. I just wipe it as well as I can and repack it with some fresh grease.

[3Phase]

T.C.,

It looks like BA80's got you completely dialed in on the wheel bearing -- nice picture!



The '80 and '81 XS11 Headlight relays have an internal latching diode that keeps the relay powered on even if the engine stops running and the alternator stops charging.

You can test the Headlight relay by jumping 12 Volts to the terminal with the White wire on it and if the relay is good it will click.

If the 10 Amp Headlight fuse is good and the Ignition switch is ON then the relay will not only click it should latch and stay on after you remove the jumper.

The '80 and '81 Headlight relay wire colors are:
White wire (the one with the diode on it) = 12 VDC relay coil power in.
Black wire = relay coil ground.
Yellow/Red = power in from the 10 Amp Headlight fuse.
Blue/Black = power out to the RLU.

The '78 and '79 Headlight relay colors are:
Yellow wire = ~7 VAC relay coil power in.
Black wire = relay coil ground.
Yellow/Red = power in from the 10 Amp Headlight fuse.
Blue/Black = power out to the RLU.


Oddly enough, the old and new style Headlight relays both use the same harness connector but they have different pinouts. Even though they can be physically connected to the wrong harness they won't work but no smoke will leak out of them (or anything else on the bike!).


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