Location of main chassis/frame ground? Ground circuit fault?

I have an intermittent fault that is getting worse. I thought I fixed it by cleaning the switch contacts in the headlight High/Low switch but it returned today.

This is what happens when the fault occurs. I switch on the key in preparation to start the bike and these items will glow dimly or faintly if Low beams are selected: right hand low beam headlight bulb filament, the 5w position lights in the upper corners of the head lamp assembly, the front position lights (in the mirror housings the turn signal lights both on), gauge display and instrument back lighting and strangely, both rear turn signals glow steady on but dimly. It sounds like the cooling fans are on and turning very very slowly even if the engine is cold. None of the devices on the left handlebar switch will work (turn signals, horn, windshield motor, hazards). If I switch to high beam the right hand headlight bulb high beam filament will dimly glow. The left one doesn't glow at all on High or Low. The tail light seems to be normally lit and the brake lights work normal.

With the High/Low beam switch in Low beam the engine will start and run normally but none of the above change. If the switch is in High beam the motor will crank over normally but it will not start. If I start the engine in Low beam and warm it up the engine dies when High beams are selected or if a turn signal or hazard lights are turned on.

I first noticed the fault when it first happened when I started the bike and the headlight and instrument lighting did not come on. It wasn't a stuck thumb starter switch. My instinct was to flip the headlight from Hi to Low or Lo to Hi and this fixed it and fixed it for the next maybe 5 or 6 times it happened over a two month period. That is why I first thought it was the contacts in that switch. It was only later when it happened more often that I began to troubleshoot what other circuits might be involved. Today I could not get the lighting to work normally by flipping Hi and Lo repeatedly. Finally it fixed itself and I could ride off.

A common link between all these devices at the front of the bike is they share a common ground wire coming out of the 24 pin connector on the left side of the frame. The exception is both rear turn signals. Their ground does not go through the big connector and both turn signals light up dimly when the fault occurs like I said above. Last week I cleaned and inspected the big connector and the connectors at the base of the 2 head light relays. They seem to be OK. I checked the bases of all the fuses for corrosion and greased them. I cleaned the Hi/Lo switch and put everything back together. Today it faulted again. I think I need to check for continuity from the 24 pin connector to frame ground lug but I do not know where it is.

Any other ideas?

What year bike?

(if applicable have the recalls been done?)

Dave,
The Ground is at the base of the gas tank on the 1300 and I don't know if you can get at it by lifting the tank as you would when changing the air filter.
I would look at the connections in the group of (two white one black and one red) as that is where the left handle bar switch and the ignition switch are connected.

Bob,
I wish I knew as much about these bikes as you do!

Dave, just a quick note, the tail lights and turn signal lights (rear) are on the same ground bolt to frame. I think that some place I read that the bolt can be loose and cause a problem.

DonMac said:

Bob,
I wish I knew as much about these bikes as you do!

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Hey Don,
The most important thing to know is how to ride. Wish I was doing more of it.

PM sent...

okbobw said:

Hey Don,
The most important thing to know is how to ride. Wish I was doing more of it.

Click to expand...

Steve and I are trying to take up the slack for you!

I distilled your original observations (hopefully I didn't miss any) into a list format, that I find easier to view.

1. When the ignition switch is in the ON position & the headlamp dip switch is in the LOW position:
   1. RH headlamp low beam glows
   2. Both 5-watt position lamps glow
   3. Both parking lamps glow
   4. Both rear turn signal lamps glow
   5. Dash illumination & display behaves strangely
   6. Cooling fans may be operating slowly
   7. LH switch cluster (turn signals, horn, windscreen motor, & hazards) fail to operate
   8. The tail lamps operate as usual
   9. The brake lamps operate as usual
   10. The engine starts and runs as usual, though no change to the issues above
   11. Note: With engine running, if (high beam, turn signals, hazard) are engaged, the engine dies
2. When the ignition switch is in the ON position & the headlamp dip switch is in the HIGH position:
   1. Starter spins the engine but will not start
   2. RH headlamp high beam glows
   3. LH headlamp high beam does not operate
3. Operating the dip switch multiple times often corrects the faults, but with no consistency.

Wow, that's some list of faults, I have a few thoughts about your situation that may be helpful.

While I agree that a faulty connection to chassis ground is likely to be the cause of the problems you are experiencing. I imagine that the 'glow' of the rear turn signal lamps is due to low voltage on the LH & RH turn signal conductors, which may well be a by product of a faulty circuit else where. Specifically, the lamps at the rear of the motorcycle (brake, tail, and turn signals) all share the same circuit to chassis ground, and as you've observed, both the brake lamps and the tail lamps are functioning as usual, which is a pretty good indication that the chassis ground circuit at the rear of the motorcycle is not at fault.

This now begs the question: Why do the turn signal conductors have low voltage?

Or perhaps a better question is: Where does the low voltage come from?

The motorcycle electrical system is essentially a 12vdc system (ignoring the internal voltages of sub systems ie. Engine Control Module, ABS Module ?), to produce a lower voltage (less than 12 volts) is pretty easy; all that is needed, is to add a resistance in series with another resistance.

Normally the motorcycle electrical system does not include series circuits, however something as simple as a bit of corrosion in a circuit connector, can be the beginnings of a series circuit, and subsequent lower voltages. Two other possible sources of series circuits are; short circuiting of multiple conductors, and lifted or broken connections to chassis ground.

Here's a study I did on the 'high-beam indicator remains on' phenomenon, a similar (perhaps) situation, which demonstrates how a missing chassis ground connection can produce unexpected results. My guess (and that's all it is) is that a faulty connection (most likely chassis ground) is allowing the voltage to travel through circuits in unintended paths (creating series circuits?), which is causing the symptoms that you are experiencing.


Now for something completely different. Did you know that the Options Connector (where the quartet harness connects) includes these circuits?

Options Connector:
Note on Fuses:
Fuse F (ABS) = Fuse E (Non-ABS)
Fuse J (ABS) = Fuse H (Non-ABS)

Too much of a coincidence? I don't know, but if you do use the quartet harness to run your farkles, it would be an easy diagnostic check, just disconnect the quartet harness, and see if the problems remain, change, or go away.

Today I took the left side tupperware off and cleaned and regreased the left switch pod connectors, the ignition switch connector, left headlight bulb connector, and the 24 pin harness connector. Since the rear turn signals glow incorrectly during the fault that drew my attention because I tapped into power and ground at the taillight for the LIN3 strobe and LED bar when I installed them. I cut off and rewired all these connections. After completing this I still had the fault.

Alas, I do not utilize the quartet harness for farkles but I will check the wiring I added for dual Fiamm horns, GPS, 12v power point, and heated grips. I can't really remember how I hooked everything up - it was 6 years ago. I know I led a 14 AWG duplex forward from the battery to power the Marinco power point in the right hand fairing pocket. From the power point connection to 12V positive I think I added another spade terminal to power the horn relay. The grips are powered off the ACC wire at the fuse box. These two power connections are fused at the source of power. The horn grounds I can't remember, the heated grips ground I can't remember. I guess the right side tupperware comes off next to check or rewire all all of this along with checking the main frame ground.

Mark said:

What year bike?

(if applicable have the recalls been done?)

Click to expand...

Oops, it's an '05.

okbobw said:

Dave, just a quick note, the tail lights and turn signal lights (rear) are on the same ground bolt to frame. I think that some place I read that the bolt can be loose and cause a problem.

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Is there just one main ground? The wiring diagram in the manual suggests this if I read it correctly.

You have checked the battery connections about a hundred times by now and people with bikes are smarter than people with boats, marine electrician, and this thought never should have entered my mind. My customers just have me trained!

Tom

Of course this fault is intermittent and I can't make it work or not work. It's magical. I switch the key on and off until it faults. So far I have not found the fault so I work the key a while longer and the fault goes away.

Today I checked the bike at 6 AM. Everything came on normally so I did a 130 mile loop. The bike performed perfectly. After doing some other stuff and letting the bike cool I started working on it. The fault is not associated with farkles and my farkle wiring. I disconnected them (horns, grips, power point, GPS) at the battery and left them disconnected. The fault appeared. I lifted the tank and checked the wires grounded to the frame under the rear of the tank. The terminals were all clean and the bolt was tight. It's not the main ground.

Messing around now with the key switch trying to get the fault to go away I determine it won't start now on Low or High beam. That's new. It cranks over strong but will not start. Maybe the ignition switch is bad? But how does the ground fault tie in with this development?

When it faulted the next time I determined this: the main stop relay and/or the fuel cut off relay does not click and the fuel pump does not spin up and pressurize the fuel system. This is different from having the engine stop switch off when it will not turn over at all. It cranks but no fuel pump sound and no start. Yesterday it would get fuel pump on Low Beam only. Touching wiggling the engine start relay and engine cut-off relays "fixed it" but this did not last and since the fault comes and goes I could not determine what action did what plus all these connectors and connections looked good and clean. I think this still points to a problem with the bank angle, engine cut off relay, or engine stop relay. The bank angle and engine stop relays connect to ground. I had to quit working so I left it at that. I'll check the relays then if they are good look under the front cowl at ground connections to bank angle sensor and instrument panel.

The service manual gives a test method to check relays. 2 of the terminals connect to 12v and you check for continuity across the other 2 terminals. I guess I make up a set of test leads with small alligator clips and use the battery to power the relay?

Thoughts?

Appreciate this is an old thread but can someone tell me where the single ground wire under the tank connects with the loom?

Barnabasb90 said:

Appreciate this is an old thread but can someone tell me where the single ground wire under the tank connects with the loom?

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Are you the one with the broken frame ground wire under there. If you could post another pic of the wire I’ll look on a sacrificial harness I have to see if it doubles back into the harness and where. It may not, but it’s worth a look see.

Thanks the first pic shows where the single black coated ground wire is attached to the frame under the tank. The piece in my hand is the other end and looks like it may be the shank of a broken connector. Immediately below is an orange connector with a bunch of green wires coming out of the ? left hand loom forward terminating there. On the other side of the bike is another piece of loom coming off the rt side coil pack running along side this is a single black covered single wire which also heads in the direction of that orange connector as there is some movement there when gently pulled. I haven't removed the upper tank as yet but will have to. Trying to avoid pulling the injectors where possible

Sorry this is the second pic showing the broken end. The wire is 9-12inches long.

Hey Anna's dad, I'm in South Jersey. If I can't get my no start problem sorted out by spring time would you like to make some money? I can trailer up to you. I don't trust the dealer down here at all. Pretty please? LOL