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Intermittent flashing brake light at start up


RPG

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My apologies if this has been answered, but my '04 RT has a little problem at start-up. Turn the ignition on and the upper brake light (can't remember the label exactly) on the dash is supposed to flash and keep flashing until you roll away. On mine, sometimes it illuminates and sometimes it doesn't. When flashing, it always goes out correctly as I move away. Anyone have any ideas? Going to change out throttle cables this weekend so seems like a good time to troubleshoot.

 

thanks,

 

RPG

 

 

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If you are changing out your throttle cables and have the tank off, why not just do a complete iABS system flush while you are at it?

 

 

 

Edited by philbytx
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Morning Rick

 

Knowing which light would help us a lot.

 

In any case (is it) dependent on IF you are holding the brakes on or not during key-on & starting?

 

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roger 04 rt
I concur with DirtRider. Odyssey PC 680 in my RT. No issues in three years. Cranks over great in cold weather (dI o a bit of late fall camping here in MI) and seems rugged as hell.

...

 

I saw this and put two and two together and make the sum equal to 5. ;)

 

I think your battery may be undercharged. The PC680 is so good that you can abuse the hell out of it and it still lights the lights brightly at Key On and spins the starter briskly, even at 80% state of charge. The problem is that when chronically undercharged the impedance seems to go up and you get a larger, momentary voltage dip when your press the starter button (less than 1 second of extreme voltage drop, I've recorded 6-7 volts). Neither the Motronic nor ABS are happy about that. Do you have a GS-911?

 

So that's my two cents. Will follow and see what it actually turns out to be.

RB

Edited by roger 04 rt
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morning DR. Yes, it's the upper "Brake Failure" light that is intermittently illuminating when the key is turned on. The lower light illuminates normally and then goes out correctly within a second or so.

 

When the "brake failure" light does illuminate, it flashes normally (1hz) until I pull away.

 

And yes, I flushed the fluid last winter.

 

thanks,

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Morning Rick

 

 

Well then I have nothing firm for you.

 

The General light being OFF, & the ABS light flashing is normal & just means that ABS is not available yet as the pull-away (ride-away) test is not completed.

 

That light not working sometimes & the brakes working as they are supposed to c-o-u-l-d mean a problematic bulb, or an occasional poor contact in the bulb socket, or a poor connection in the wire circuit, or a poor connection in the ABS controller connector itself, or something in the ABS controller.

 

As long as you are putting cables in you might look at the ABS connector, see if the wire harness is not damaged, & if feeling frisky you might install a new dash bulb & clean the socket contacts.

 

I would normally agree with Roger on the possibility of a slightly low battery but I have camped with your group before & sort of know about your riding/breakfast thing so I'm pretty sure you ride lots of miles once out of your driveway.

 

Added: once you have the plastic removed you might get that light flashing then wiggle & move things (wires)(bulb)(etc) around to see if you can get it to quit, or better yet to come & go.

Edited by dirtrider
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good stuff DR. We're on the same page. I think I'll start with the bulb, contacts, and work my way back to the ABS controller connection.

 

And my new job gives me a 120 mile roundtrip each day to Lansing and back so living the dream right now!!! Some interesting back roads out in this area. Just have to keep an eye out for the four legged critters as the mutilated carcasses are already starting to pile up.

 

thanks very much,

 

RPG

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yep, you got me.

 

Yes, I have a GS-911. Last time I checked, minimal voltage drop on the battery during engine crank. Can't remember the exact figures, but another cue is that the clock doesn't reset. My gut feeling is that it's a bulb/connection issue as DR pointed out so I'm going to head down that path first. But I need to plug in the GS911 anyway as part of my spring prep/maintenance, just to make sure no codes are present. Thanks for reminding me.

 

I concur with DirtRider. Odyssey PC 680 in my RT. No issues in three years. Cranks over great in cold weather (dI o a bit of late fall camping here in MI) and seems rugged as hell.

...

 

I saw this and put two and two together and make the sum equal to 5. ;)

 

I think your battery may be undercharged. The PC680 is so good that you can abuse the hell out of it and it still lights the lights brightly at Key On and spins the starter briskly, even at 80% state of charge. The problem is that when chronically undercharged the impedance seems to go up and you get a larger, momentary voltage dip when your press the starter button (less than 1 second of extreme voltage drop, I've recorded 6-7 volts). Neither the Motronic nor ABS are happy about that. Do you have a GS-911?

 

So that's my two cents. Will follow and see what it actually turns out to be.

RB

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  • 4 weeks later...

Finally got my dash pulled apart last night. The bulb ohmed out OK, and swapping with another working dash bulb did not fix it. I cleaned the contacts on the connector and voila, it started flashing. Cleaned up everything real good, re-installed everything and of course, my luck, it stopped flashing.

 

When I get a chance, I'll troubleshoot further but I believe the issue is either the ground (this light has a separate ground according to the schematic) or the connector (#10, 11).

 

In the attached, does anyone know where connector 10, 11 is located? I'm guessing there's some dirt/corrosion there. Also, I need to check the signal from the relay output to the bulb connector.

 

thanks, RPG

Edited by RPG
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A little more troubleshooting last night. Pulled the Tyco relay (the blue one, 6136-1393417) and after checking the already cleaned contacts, re-inserted and the Brake Failure light is flashing normally again.

 

The relay coil (pins 1-2) ohms out at 100ohms, which might be normal since it's a flasher relay.

 

As a matter of course, I would like to replace it just to monitor. Does anyone know if the relay is available at local Auto Parts stores?

 

thanks,

 

RPG

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dirtrider

Morning Rick

 

You might take that relay to your local auto parts store & see if they can match it up.

 

Nothing special about that relay, just the terminals vs internal circuits need to match.

 

Just take note that your original relay has a clamping resistor so be sure your matched relay has some sort of voltage spike protection (with that relay flashing on & off it tends to send a voltage spike as the pull-in coil collapses on each flash)

 

ABSrelay_zps440517f8.jpg

Edited by dirtrider
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I saw that on the label D.R. Thanks for pointing it out. For a second I thought it was a diode but it's clearly a resistor as you say. There's a auto parts store right by my house that should have one.

 

But the engineer in me wants to tear into it further for more diagnosis...........Just to have some fun I might run a separate 12v source to coil terminals 1,2 and measure resistance across the switched side just to see if it varies. (which it shouldn't).

 

RPG

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dirtrider

Afternoon Rick

 

 

Yes, there is both resistor & diode type clamping.

 

Diode is a little better at always-on power saving (especially if many relays in use) but is obviously polarity sensitive so has a more limited usage per relay.

 

On the other hand the resistor clamping is not polarity sensitive so the same relay has more uses but is does use slightly more power when energized.

 

Then there is always the option of adding your own external clamping if you find a non clamped relay.

 

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  • 3 years later...

RPG,

 

Did you find the source of our telltale light problem described in this post? I have a 2004 R1150RT also and it just developed a similar, if not the same issue you've describe. After I turn the ignition key on I can hear the relay clicking, yet no light. After some time, 15-30 seconds it seem to start lighting in unison with the relay as it should.

 

Thanks,

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RPG,

 

Did you find the source of our telltale light problem described in this post? I have a 2004 R1150RT also and it just developed a similar, if not the same issue you've describe. After I turn the ignition key on I can hear the relay clicking, yet no light. After some time, 15-30 seconds it seem to start lighting in unison with the relay as it should.

 

Thanks,

Morning bewareboy,

 

I believe my issue was dirty contacts for the bulb holder. The problem hasn't occurred in quite some time now.

 

RPG

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RPG,

 

Thanks, If you don't mind, another question.

 

Did you ever replace the relay or just end up pulling, cleaning contacts and reinstalling. Sounded like from the full thread, you cleaned some things, but at that time it didn't seem to isolate a smoking gun? If you ended up just cleaning everything and coincidentally or rightfully it cleared up the continuity issue that good to know, I guess. If you also replaced anything, might that have been the faulty component? You mentioned replacing the relay and doing a destructive examination of the old relay?

 

I'm a bit puzzled with my ride as last year I replaced all the telltale lights, cleaned and used dielectric grease on all connectors under the front fairing/dash. This spring I pulled all fuses and relays to clean connections and apply dielectric grease to them. Everything has been working great until a week or so ago. Maybe this is a reason to look more closely at that relay. I haven't tried to do any troubleshooting as of yet though.

 

The only other electrical work this past spring was to add the 0.5v increased Voltage Regulator ~(13.7v to 14.2v) from EME to the alternator to help with the Odyssey PC680 battery charging while riding.

 

Thanks again.

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Morning bewareboy

 

You might remove the ABS warning light relay then measure the bulb resistance from terminal (4) to ground (this should show the light circuit + bulb resistance)-- (if it shows open then you have an open bulb or circuit open)

 

Then check for 12v at relay terminals (1) & (3) with key on (maybe set this up the night before to see if you have the 12v at those relay terminals at next morning first key-on)

 

What kind of dielectric grease did you use on the bulb contacts? In the auto industry we have seen some (intermittent) bulb contact resistance issues if spark plug boot type dielectric grease is used on low current bulb applications.

 

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D.R. Thanks for the diagnostic suggestions. Will do that and see what shows. Relative to the dielectric grease, it is Wurth brand. I am trying to remember, but I don't think I used the dielectric grease on the bulb/socket connections, just the harness connectors all around the bike and the fuses / relays in the box under the seat. If I get to the point of removing the bulb, I will check to see if there is any dielectric grease on them.

 

Thanks,

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D.R. Thanks for the diagnostic suggestions. Will do that and see what shows. Relative to the dielectric grease, it is Wurth brand. I am trying to remember, but I don't think I used the dielectric grease on the bulb/socket connections, just the harness connectors all around the bike and the fuses / relays in the box under the seat. If I get to the point of removing the bulb, I will check to see if there is any dielectric grease on them.

 

Thanks,

 

Morning bewareboy

 

If you used dielectric grease on the tangs of the ABS warning light relay then you might remove that relay & try cleaning the relay & socket terminals to see if your problem goes away.

 

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