Cooked Headlamp Harness

[tomatocity]

Those spade connectors were installed by my dealer to keep me on the road while a new harness
was in route. These connectors were used for 4000 miles . Now the new harness is installed and the
old one and the origional plug is all going back to Yamaha for inspection . What puzzles me is why just
this one side continues to be a problem . Could it be the bulb ?

Can you swap bulbs side to side?

 

[Mellow]

This happens to both sides, it's just the left one seems to have more extreme issues.

 

[mcbrien]

Can you swap bulbs side to side?

Damn , thanks for useing your noodle. I will switch them and see if the other side melts .
Next spring I should have some results ::010::

 

[mcbrien]

:lamp: My dealer has a tempature gun and replacement bulb so Monday
I will ride over and check temp's , if it's hotter on the opposite side now I
will switch to a new bulb and recheck .

 

[Dallara]

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Since I have been following this issue since the beginning I thought I might chime in here and offer up a few thoughts and observations...

One, I honestly don't think there is any one single, solitary cause to this problem. IMHO, it is a combination of things that leads to the failure. As has been noted here so often, resistance is what's driving the problem, but I don't think it's any one particular spot of resistance that one can pinpoint. Instead, it is a culmination of the plug pins from the harness to the sub-harness being marginally sized for their purpose, the wire being borderline for it's use (either due to materials, construction, size, or combination of these factors), and the plug to the bulb itself being perhaps just adequate for the job. If all these components just meet their design specification, or even slightly exceed it, then there is no problem and the headlamps function OK without any discernible problem...

However, if any one of these components or their construction, materials, etc. fall just on the low side of the factory design spec then suddenly you have excessive resistance, excessive heat, and either a cooked, crumbling headlamp plug or a melted, burned, toasted wire... And failure. Certainly there are ways to address any single one of these potential areas the harness can fall below spec - the plugs or the wire, etc. - and *PERHAPS* this will luckily enough keep your harness from failing. However, if you address one and it is, indeed, another part of the *chain* of the harness then you are still going experience failure at some point. Just note the folks who have tried different spade plugs, or dielectric grease, or modifying the existing bulb plugs, etc. and then have still had a failure on down the road. That point alone should lead one to the logical conclusion that there is more than one factor involved here.

Mind you, I obtained all the parts and materials to construct what I believe would be a truly foolproof, dead-bang reliable headlamp sub-harness, then never built it. Instead, I installed the factory replacement harness Yamaha gave me and have been running it for thousands and thousands of miles since - trouble-free. From all appearances that replacement harness was identical to the original harness in mine that cooked off. And it was that original harness which precipitated me to start this thread. One day I still plan to build the *improved* harness, but until then I just watch the one I have and continue to ride, ride, ride.

There is no doubt in my mind that Yamaha spec'ed a headlamp sub-harness that would adequately serve the bike with standard 55-watt bulbs, but that doesn't necessarily mean that their supplier who made the harnesses manufactured each one to actually meet or exceed that specification. This is where I *THINK* the problem lies, and it's why one harness works fine while others fail. Perhaps now Yamaha has a good enough handle on quality control and inspection of the harnesses that any replacement harnesses will not have any issues. That said, if you have one that has *NOT* failed and you want to insure that yours doesn't then the logical conclusion is that you have to address *ALL* the potential areas that might cause the increased resistance, its subsequent heat, and the inevitable failure should one component in your harness be suspect.

Just because the ultimate failure point is at the headlamp plug or wire immediately leading up to it does *NOT* mean that's necessarily the only spot of increased resistance. There could be enough resistance elsewhere in the harness that initially leads to increased heat, which in turn leads to further increased resistance and heat, which then leads to expansion of the headlamp spade plug ends, which further increases resistance and ultimately - failure. In other words, it could be a *runaway* effect started by component inadequacies elsewhere from the plug itself. It's just that's where it finally fails because that's where the problems leading up to the failure manifest themselves in the greatest deviation from spec.

By all means, it doesn't hurt to do any or all of the various tips and tricks in this thread... bending the spade tabs on the headlamp plug to increase tension (and therefore contact force), filing the ends of the headlamp plug to allow it to set deeper on the bulb tabs, dielectric grease to lessen corrosion and act somewhat as a heat sink compound, etc., etc., etc.... But until the entire harness is addressed as a *complete system* and modified accordingly then you will never be 100% sure the problem will not occur.

Just my two centavos... YMMV.

Dallara




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[Don in Lodi]

No, take my word for it, heat at the headlamp connector means a bad connection right there, nowhere else. I may not be into farkles, but have been an electronic tech for nearly 34 yrs. The burn is at the lamp, there is the point of bad connection. There is no other possibility.

::008::

 

[Checkswrecks]

Those spade connectors were installed by my dealer to keep me on the road while a new harness
was in route. These connectors were used for 4000 miles . Now the new harness is installed and the
old one and the origional plug is all going back to Yamaha for inspection . What puzzles me is why just
this one side continues to be a problem . Could it be the bulb ?

Re-read my last post, where I pointed out that some energy is lost as heat at the bulb, so the power side will run hotter.


You might point out to your dealer that the tin plated connectors are worth the extra little that a box would cost.

 

[jc450]

As an automotive electonics engineer I would say the design looks marginal. I dont see much in the area for heat transfer, connections are the weak point of any circuit so no surprise they are the first to go. 55W is alot to dissipate in a sealed plastic enclosure.

jc

 

[mcbrien]

After new harness installed and bulbs switched to opposite side right side is still hotter.
200 degrees on left and 220 on right .

 

[Firefight911]

Just for statistical input, I'll now add my name to the hat on the headlamp issue. My right headlamp went out during my trip this summer. Replaced it and it worked fine. Had an intermittent not working scenario a few weeks back that resolved with a jiggle of the harness connector. That was my indicator that it was a connection issue not a lamp issue.

Took my bike in to the shop and they replaced the entire headlamp assembly, harness, etc. Mine had overheat markings on the harness and had created a substantial "haze" in the glass so it was completely swapped out under warranty. Dealer has crimped the connections and added dielectric grease at the behest of Yamaha. My entire assembly has been forwarded back to Yamaha for analysis. My dealer has indicated that Yamaha is very aware of the issue and is looking in to it.

I will repeat this AGAIN; if you have an issue you need to run it through the dealer network and/or the NHTSA reporting website. They can't and won't fix it if you are too lazy to address the issue properly and through appropriate channels.

I will add that my dealer, Roseville Yamaha, never balked or raised one hurdle to getting this resolved. They made one phone call to Yamaha and had approval to replace/repair whatever needed to be done immediately, no questions asked.

 

[jajpko]

Just for statistical input, I'll now add my name to the hat on the headlamp issue. My right headlamp went out during my trip this summer. Replaced it and it worked fine. Had an intermittent not working scenario a few weeks back that resolved with a jiggle of the harness connector. That was my indicator that it was a connection issue not a lamp issue.

Took my bike in to the shop and they replaced the entire headlamp assembly, harness, etc. Mine had overheat markings on the harness and had created a substantial "haze" in the glass so it was completely swapped out under warranty. Dealer has crimped the connections and added dielectric grease at the behest of Yamaha. My entire assembly has been forwarded back to Yamaha for analysis. My dealer has indicated that Yamaha is very aware of the issue and is looking in to it.

I will repeat this AGAIN; if you have an issue you need to run it through the dealer network and/or the NHTSA reporting website. They can't and won't fix it if you are too lazy to address the issue properly and through appropriate channels.

I will add that my dealer, Roseville Yamaha, never balked or raised one hurdle to getting this resolved. They made one phone call to Yamaha and had approval to replace/repair whatever needed to be done immediately, no questions asked.

You have a great dealer! Mine looked at the connectors and wire and said, "It sure gets hot in there".
That's why I just went ahead and took care of the problem. It was just less of a hassle. LOL

 

[Dallara]

Just for statistical input, I'll now add my name to the hat on the headlamp issue...

...Took my bike in to the shop and they replaced the entire headlamp assembly, harness, etc. Mine had overheat markings on the harness and had created a substantial "haze" in the glass so it was completely swapped out under warranty. Dealer has crimped the connections and added dielectric grease at the behest of Yamaha. My entire assembly has been forwarded back to Yamaha for analysis. My dealer has indicated that Yamaha is very aware of the issue and is looking in to it.

I will add that my dealer, Roseville Yamaha, never balked or raised one hurdle to getting this resolved. They made one phone call to Yamaha and had approval to replace/repair whatever needed to be done immediately, no questions asked.

Gotta' say it's great to hear that Yamaha Cypress is finally "very aware of the issue and is looking into it..."

Nearly a year ago when I first reported this issue, and spent quite a bit of time on the phone myself with Yamaha reps discussing it (as did my dealer), I got the prototypical "This is the first we've heard of it" song and dance. At first they wanted the sub-harness back, but when they realized they couldn't get me another one for quite a while they gave me the go-ahead to continue to ride with it and/or repair it... Accepting a large number of pictures from both myself and the dealer as the "evidence" and "documentation" they needed. As has been noted in this thread I finally did get a *new* sub-harness under warranty, free-of-charge, but has also been noted the replacement harness from Yamaha looked no different in materials or construction than what cooked off in the first place.

Just nice to know now that they are not ignoring the problem as no more than an anomaly, and are actually admitting it is an issue they need to address.

Good on you, Firefight911! ::008::

Dallara



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[JohnB]

Just for statistical input, I'll now add my name to the hat on the headlamp issue. ... it was completely swapped out under warranty.

Was your warranty period still in effect or was it replaced after your warranty period had expired?

 

[Firefight911]

It was after the initial new bike warranty expired, however, I have the Y.E.S. extended warranty which provides an additional 4 years of coverage.

 

[ErnsTT]

, but I don't think it's any one particular spot of resistance that one can pinpoint.

Oh yes there is, and it is actualy so evident that all the melted harnesses show the same heat patterns, wires getting grey from the sub-optimal contact point at the Ground terminal of either or even both lamps, according to the batch of crimpydinky terminalhousings.

Its also almost always as far as i've seen evidence the *ground* wire, so if it was an overload problem, both terminals would be affected, but i havent seen any positive leads going without the ground wire turning grey first...

An the solution is as simple as can be, no need for any new parts, one could even dump the lousy crimpydinky casting, and just put the two terminals right on the H7, because the reflector is plastic, it won't even matter which lead on which terminal

Then you would directly feel if the terminal hasn't enough springforce by the heat treatment right away, then you better crimp another on the lead, the only way to get brass springy again is by rolling or pressure forces, you cant heat treat it like steel, any heating will soften it, even if you quench it directly in the coldest watter available, it actually will get even softer when you quench brass after heat treating it in cold water ... (1st lesson in "gold" smithing)

 

[sail2xxs]

A few weeks ago, I ended up spending an unplanned night at a hotel because both of my headlights went out. Swapping the fuse, checking the bulbs, etc. made no difference. Jiggling everything around didn't make a difference either. The next day, after going through the same routine, the lights worked, albeit with reduced output. Not really knowing much about electrical stuff, I waited until yesterday's 52k service for the tech to take a look at it. This time, the connector in the right hand side of the fairing was the culprit - it had clearly overheated and was slightly melted/browned. Fresh harness is on order.

The only other tiem I have had a harness issue was with the connector to the right headlight bulb, which melted to a a crisp.

Chris

 

[EricV]

Any chance we can get a pic of exactly what connector melted on you? This is the first I can recall of a connector other than the headlight bulb ones having an issue. I'm guessing this is the other end of the headlight harness?

 

[sail2xxs]

Any chance we can get a pic of exactly what connector melted on you? This is the first I can recall of a connector other than the headlight bulb ones having an issue. I'm guessing this is the other end of the headlight harness?

EricV,

Yes - it is the other end of the headlight harness. It didn't melt totally, just a bit - more browning than anything else on that one. The other connector has a significant amount of corrosion. I don't have a pic handy at the moment; have to take the right hand fairing cover off for it. If you happen to have removed yours in the past, you may remember a rubber boot with a bunch of connectors in it. It's one of those.
When the connector was replaced last time, the tech and I both noticed that there was some corrosion of the other connectors in the boot. It is supposed to keep the connections dry; instead, it actually keeps more water/humidity around them, despite having a few drain holes at the opposite (aft-facing) end. We liberally taped the forward-facing end to see if this would reduce water inflow while riding in heavy rain or doing water crossings. It doesn't seem to have helped a lot; neither did the copious amounts of dialectric grease used on the connectors before taping everything up.

When the replacement harness goes in, my plan at the moment is to again use the dialectric grease, then use liquid tape over everything to create as close to an impervious connection as possible. Not sure how else to tackle it at this point, short of removing all the connectors, wiring the looms together without them, and liquid taping the heck out of it.

I'm going to start researching waterproof connectors - they're on my boat, so I know they exist!

Chris

 

[EricV]

Thanks Chris. I long ago turned that rubber boot around to face the direction I thought it should, open end to the rear of the bike. It's a little work to get the wires out one by one and back in, but not impossible by any means. It does have a small drain hole in the closed end of the boot, but I left that alone.

I'll peek at those connectors next time I'm in there. I've got some ceramic H7 connectors, but have been putting off doing anything with them since I haven't had any issues as yet at 34k.

 

[Dallara]

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What was that about where some were saying that only the headlamp bulb plugs were the problem, and that the rest of the headlight sub-harness was more than adequate?

The more this problem keeps rearing its troublesome little head the more I believe Jim Davis at Eastern Beaver was entirely accurate and correct in his assertion that the entire headlamp harness - that's plugs, wiring, insulation, etc. et al - from where it plugs into the main harness all the way to the headlamp bulbs, high-beam solenoid shutter triggers, and marker lamp sockets, is all very much *on-the-edge* for the current it handles...

And that the base of the problem *STARTS* with the small plug - and tiny connector pins inside that plug - where the headlamp sub-harness plugs into the main wiring harness. Yes, the entire sub-harness is subject, but the problem starts at that plug.

Just my two centavos... OMMV.

Dallara





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