Intermittent Electrical Issue

[red2kcbr]

After a couple of wet trips of 1,200 miles each I notice the '14 ES is running...wrong. Felt like a fueling problem, surging at low RPM, hard to maintain a steady speed even with cruise control set. It would stagger a bit, then resume normal running. It was happening over many tanks of fuel so I ruled out bad gas. Only mods are TBR cans, block-off plates, Garmin GPS, and a Givi V47 with the Givi brake light LEDs. Plugs have 5k miles, standard NGKs. No codes from ECU. It even died at a stop sign once and once leaving a light. I could mitigate the poor running by staying in a lower gear to keep it spinning faster. Using the '14 FSM to check coil readings and TPS values, found them within limits. We were leaning towards a bad coil that only manifested the issue at normal operating temps.

Fast forward a week, and I noticed the Givi brake lights flickering intermittently. Checked the connections by wiggling switches and wires and managed to kill the Givi lights completely. Aha, I thought, a clue! Went riding and the surge was gone! More troubleshooting traced the poor connection to the switch between the box and the 357 rack. Some scraping of the contacts and now lights work and bike runs right.

Could that poor connection have been the cause of such a weird problem? I read the threads regarding electrical issues. Seems to be sensitive to poor ground. The Givi brake lights are soldered in to the yellow brake light wire, wrapped with shrink tubing, and grounded to the aluminum seat frame, paint scraped to bare metal. Would a Fuzeblock be a better solution? I still need to add a 10 amp socket for compressor power.

Got a 3,600 mile trip coming up, just looking for ideas.

Thanks in advance. Couldn't survive without this forum.

 

[MrZappo]

Unless there is some gross error in your wiring, I can't see how the two things could be related ... Based on how you described your wiring, it is obvious that this isn't your first rodeo so probably rule out error ?

You said you found an issue with the "switch" between the case and the 357 ... I assume you meant the "pressure connector" ? I am not aware of a switch in that set up ... Is it possible something was shorting to ground ? I would have thought that would create an obvious sign like "fire and smoke" which I assume you would have mentioned ...

A fuseblock is always a good thing although I don't normally utilize it for brake light led wiring as the current is so small and the connections are "right there" ... No sense running all the way to the fuse block when the switched power is back there anyways ...

I also would not (personally) go through the trouble to connect Givi LED's ground to the aluminum frame as there is really minuscule current draw on those things. I would likely just tap into the negative feeding one of the brake lights ... In fact I did do that as I have the same set up as you ...

Those SR357 racks are great but those pressure connectors are pretty cheesy ...

Are you able to replicate the issue by wiggling the case or doea it seem to be totally gone ?

 

[Niehart]

Also make sure your at at least 1100 RPM when idling.

 

[red2kcbr]

Mr Z: yes, the pressure connection. No shaking or wiggling reproduces the intermittent brake light.

Niehart: idle is good.

The trunk stays on the bike; too damn useful to take off. It's been on since I did Fred's safety pin mod. I did add another washer to take up a smidge of slack in the pin. I felt (heard) the trunk rattle a bit over rough roads, but it's better now the pin tightens up the mating of trunk to 357.

I'm paranoid, but am I paranoid enough?

 

[Donal]

Mr Z: yes, the pressure connection. No shaking or wiggling reproduces the intermittent brake light.
Niehart: idle is good.

The trunk stays on the bike; too damn useful to take off. It's been on since I did Fred's safety pin mod. I did add another washer to take up a smidge of slack in the pin. I felt (heard) the trunk rattle a bit over rough roads, but it's better now the pin tightens up the mating of trunk to 357.

I'm paranoid, but am I paranoid enough?

Just because your paranoid doesn't mean that things are not ACTUALLY going to go wrong..................

 

[rbentnail]

Just for S&G, I would run the ground not to the seat pan but back to the battery if the problem pops up again. Aluminium is such a prolific corroder, the rapidly developed "skin layer" can be problematic.

 

[red2kcbr]

Finally seem to have this issue resolved.

The Givi brake light issue was a nasty coincidence, just to **** me up, I'm sure. MrZappo called that one right away.

Service manual mentions a scenario I was too familiar with: no check engine light but bike is not running right. First item on the troubleshooting list is the TPS. Hmm...

A quick forum search (non-compensated spokesperson)

turned up JustHoward thread, which links to ionbeam how-to for TPS replacement.

Boats site had the best price at $101 so I ordered one, part number 2S3-85885-00-00.

GenIII TPS sits a little differently, but the engineers managed to keep one of the 25-torx security screw heads nearly inaccessable, so that is still the same.

Followed ionbeam's excellent write-up and went for a two hour test ride.

No recurrence of symptoms, specifically a stumble between 3 and 4 thousand rpm, cruise set or not. I'm thinking this issue is resolved, pending next road trip.

Thanks for all the help.

 

[Bill Lumberg]

Your issue sounds like it was in the ballpark of my issue. Mine is the same as yours was, but to me, it feels like the stumble is more related to where the throttle is than a specific RPM, but that may just be perception. Mine happens cruise or throttle too. Mine is under warranty, so I'm trying to find a good time to put it in the (dealership) shop.