Gen III : front brake light switch and cruise control...

I have a 2014A. I like to have the front brake lever turn on the brake light at a lighter touch than what it is.

So I drilled a small indentation on the lever where the front brake switch pushes against. Then it took only 1-2mm of lever to trigger the brake light before the brake engaged. Good. But then I noticed that the cruise didn't engage anymore, since it considered the front brake was on (even though the brake light wasn't on when the lever was released).

Is there a way to have the front brake lever trigger the brake light sooner without affecting the cruise?

I guess not. But it doesn't hurt to ask

I already filled the indentation with JB Weld to restore everything

Thanks.

There are two sets of contacts on both the front brake's lever and the rear brake's pedal. One set is for the lights, the other is for the cruise control. All switch contacts operate opposite to what you may expect; they are all normally closed contacts and go open circuit when you pull the lever in or step on the pedal. In the case of the brake lights, that de-energizes the brake light relay, which allows contacts in it to turn the brake light on. In the case of the cruise, loss of continuity sends a signal to the ECU to drop the cruise.

These contacts are inside of the same single switch housing, so I would expect them both to go open at the same time. In any case, I don't see how you would separately adjust the two function unless you added a second physical switch with normally closed contacts that could be adjusted separately.

Thanks Fred. So I guess the cruise's contact was activated earlier than the brake light contact inside this switch. Because the brake light wasn't on, but the cruise wouldn't engage after I drilled the indentation.

If the two NC contacts operate at different amounts of lever movement you might try transposing the connections to the switches.

Connect the brake circuit wiring to the more sensitive switch -- the cruise control switch.

Connect the cruise control circuit to the less sensitive switch -- the brake circuit switch.

Why are you wanting the brake light to energize when you haven't actually applied the front brake?

Are you sending morse code to someone behind you?

mikerider said:

Thanks Fred. So I guess the cruise's contact was activated earlier than the brake light contact inside this switch. Because the brake light wasn't on, but the cruise wouldn't engage after I drilled the indentation.

Click to expand...

This is the way it's designed. The idea is that the CC disengages before the brake lights (and brakes) are activated. I spent a couple of weeks sorting out the workings of the switches in the process of tracing down some munge that had gotten into this switch. IIRC I believe there is also a fault detection mechanism that determines a case where the brake lights are on and the CC is still engaged that will cause a fault, disabling the CC until the bike is switched off and on again.

Ah... this explains why the switch contacts would intentionally be staggered that way. I did not know it would throw a code when that happens.

Constant Mesh said:

If the two NC contacts operate at different amounts of lever movement you might try transposing the connections to the switches.
Connect the brake circuit wiring to the more sensitive switch -- the cruise control switch.

Connect the cruise control circuit to the less sensitive switch -- the brake circuit switch.

Why are you wanting the brake light to energize when you haven't actually applied the front brake?

Are you sending morse code to someone behind you?

Click to expand...

Would that be possible without cutting and splicing the wires?

And he is not wanting to turn on the brake lights without applying the brakes. The Gen3 front brake requires a bit of pressure before the brake lights energize. It is possible to have a considerable amount of stopping force applied with no brake lights to alert the vehicle behind. I don't like it either.

Fred W said:

Ah... this explains why the switch contacts would intentionally be staggered that way. I did not know it would throw a code when that happens.

Click to expand...

I did not know that either. This little brake light issue does actually irritate me.

Exactly! There were some situations when I wanted to turn on the brake light (I had a brake light flasher too) without actually having to show down, when a car was coming up too fast on my six.

I just looked up the FSM and the rear brake pedal does have an adjustable brake light switch and the cruise control turns off only when the rear brake light switch was triggered (unlike the front). If it could be adjusted to turn on the brake light without applying pressure to the brakes, I can live with it

I discovered the exact same issue. In my case, I felt that it was taking way too much front braking before the brake light would come on. In stop & go traffic where I was only using the front brake, the brake light was not coming on until I was braking moderately (not often enough).

So, I drilled and tapped the portion that acts as an actuator to the front brake light switch and installed a 1/4-28 stainless steel set screw for adjustment:



I adjusted it to have the brake light come on with moving the brake lever to a point just before braking action. Cruise non-functional. I had to back it off to just about the stock position so the cruise would work. Still have the same problem with too much brake before the brake light comes on. I try to use the rear brake (properly adjusted so the light comes on just as braking occurs) to get around the problem. I don't like it.

Dan

Damn. I never knew about this undocumented "feature" until this week. Now this is going to bug me until we fix it.

So, thinking this through...

They delayed the brake light actuation point so the ECU wouldn't throw an error code if it saw the brake light on but the cruise still engaged, which might happen to a minor extent if they were triggered simultaneously. But the lever motion required between the two is too much, which creates an unsafe situation where the brake light may not come on when you are lightly braking.

Seems like a better solution would have been to have both switch contacts close simultaneously, and early in the lever stroke, and just put an electronic delay on only the brake light signal going to the ECU to filter out the false errors.

Maybe you need to add a momentary pushbutton switch to turn on the brake lights anytime you want them.

Since they are relay actuated you'd be switching a tiny relay coil current with the pushbutton. An easy circuit mod.

Obviously Yamaha doesn't want runaway bikes on their hands. They've included some switch redundancy in their cruise control scheme.

Cruise controls have caused headaches for some of the car companies.

Fred W said:

Damn. I never knew about this undocumented "feature" until this week. Now this is going to bug me until we fix it.
So, thinking this through...

They delayed the brake light actuation point so the ECU wouldn't throw an error code if it saw the brake light on but the cruise still engaged, which might happen to a minor extent if they were triggered simultaneously. But the lever motion required between the two is too much, which creates an unsafe situation where the brake light may not come on when you are lightly braking.

Seems like a better solution would have been to have both switch contacts close simultaneously, and early in the lever stroke, and just put an electronic delay on only the brake light signal going to the ECU to filter out the false errors.

Click to expand...

This makes a lot of sense, good analysis. The only thing I wonder is why they didn't just use the brake light switch (and subsequent circuit activation) as a trigger to interrupt the cruise. This is how the Audiovox works, cruise disengages as a slave to the brake light actuation.

My biggest concern is safety. The chance of a rear-ender is heightened because of this issue and I don't like it at all.

Dan

I agree. Why couldn't they keep-it-simple and just use a single contact brake light switch that turns on the brake light and turns off the cruise at the same time at the first click?

My guess would be they want the safety of the cruise circuit being "fail safe". The way it is now it will only work when you have continuity through the two brake and clutch switches.

The brake circuit is a mixed bag.on 2nd and 3rd Gens in that there are two relays that are used to turn the brake lights on. That's a lot of mechanical stuff to possibly go wrong that could affect the cruise control's ability to drop out of cruise once set.

For a long time now I've had a problem getting the cruise control to always engage. I suspected that the cc thought the brakes were still on so it said I won't work.

Looked at the service manual and saw that the rear brake could be adjusted so the light would come on sooner or later depending on how you adjusted it. So I experimented with the adjustment a bit. Sometimes the cc would work, sometimes not. So I continued to work with the adjustment until the brake light stayed on all the time then backed it off a little so the brake light turned off. The next ride the only way I could get the cruise control to work is to message the brake pedal several times until the cc would engage. I thought that darn brake light must still not be turning off all the time or at the very least the cc switch thought it wasn't.

So once again I played with the foot brake adjustment and all seemed good. When I pressed down on the brake lever I could hear the relay switch so maybe I had fine-tuned it enough. Went on a long ride and discovered the cruise control wouldn't engage at all. The next stop looked at the brake light and it was on all the time. Tried to adjust the foot brake again to no avail so rode the rest of the day with the brake light on all the time and no cc.

So my next question is, after reading all through this thread, could I have a bad relay because now no adjusting to the brake pedal will turn off that light.

I'm stumped, help please!

Garry

its just rain said:

...So my next question is, after reading all through this thread, could I have a bad relay because now no adjusting to the brake pedal will turn off that light.

I'm stumped, help please!

Garry

Click to expand...

Are you quite sure your brake lever isn't sticking? The bearing can seize a bit, it does need occasional lubrication.

I jacked mine up by not getting the switch for the rear brake fully nested in the housing. As for brake light actuation as a warning, I just use my rear brake lever.

Also, be aware that both the front and rear brake switches have two sets of contacts. One set of normally closed contacts in each switch is used to turn the brake light on. Only time you open either set of contacts the brake light goes on.

The other set of contacts in each of the switches is used to cancel the cruise control. So for the cruise to engage, not only does the brake light have to be out, but those secondary contacts have to be right. And then there is also the switch that opens when you rotate the throttle backwards (CCW). No shortage of reasons the cruise wont engage.

Clutch switch too, I assume.