Please help me troubleshoot headlights

Hi,

Can anyone please help me troubleshoot an issue with my headlights? I recently installed the Oxford heated grips and in the process was poking and prodding around in my relays on the left side of my seat and I think I messed something up. The heated grips are connected directly to the battery at the moment and they are working fine but now my headlights will not turn on. Everything else is working.

I have a very basic understanding of these things and would really appreciate suggestions of what I should do next. Note that I've checked all the fuses on the right side of the seat and the two that are plugged in above the battery (what is this part?). They're all fine.

Here's a picture of the relays I was poking at:
Relays on left of seat

Is someone able to identify where these wires go and what the relays are intended for in clearer detail?

Here's a table of the voltage that I measured between 1/2/4/5 as indicated in the picture:
Table of voltage differences

If I connect the wires at #2 the headlights turn on when the key is turned or if there is ignition and the hi/low switch works. I'm tempted to just cut out the relay and leave these connected but I'm guessing there's a good reason that I shouldn't do this...?

I've tried switching the relays and there is no change in behaviour (bike starts and runs fine, headlights still don't turn on).

Thanks in advance for any help you can provide,
-Peter

The headlights only turn on when the bike is running, so the first question is did you start the bike?

Thanks for replying. Yes I start the engine and the headlight doesn't turn on. You can see the voltages in the table (2nd link).

Before electrical engineering gets too deep, pull the lights and check the filaments.

Don't switch relays unless you know they are the same part number and/or configuration. There is a relay for the headlights that is operated by the ECU.

If you're going to measure voltages first measure at the headlamp plug.

Engine running, the left headlamp plug, Black wire with green tracer should give you 12 plus VDC

Engine running, the right headlamp plug, high beam switch turns on, black wire with yellow tracer should give you 12 plus VDC

The black wire in each plug is ground. Use that black wire to insure you haven't lost a ground path.

As mentioned, check your filaments on all your lamps.

Edit: If you have a naked bike with a single H4 headlamp the color codes with still be the same.

Motogiro said:

Don't switch relays unless you know they are the same part number and/or configuration. There is a relay for the headlights that is operated by the ECU.

If you're going to measure voltages first measure at the headlamp plug.

Engine running, the left headlamp plug, Black wire with green tracer should give you 12 plus VDC

Engine running, the right headlamp plug, high beam switch turns on, black wire with yellow tracer should give you 12 plus VDC

The black wire in each plug is ground. Use that black wire to insure you haven't lost a ground path.

As mentioned, check your filaments on all your lamps.

Edit: If you have a naked bike with a single H4 headlamp the color codes with still be the same.

Click to expand...

Hi,

The filaments are fine. If I bypass the relay and connect the circuit labeled as #2 in my picture the lights work as long as the key is turned or engine running.

There's no voltage at the bulb socket.

I confirmed the relays are the same part number before switching them.

There's no black wire coming out of the relays.

Do you have any tips how I can learn about and troubleshoot whether this is an issue with my ECU?

has somebody previously tapped into the headlight circuit for the heated grips relay?

prock said:

Hi,

The filaments are fine. If I bypass the relay and connect the circuit labeled as #2 in my picture the lights work as long as the key is turned or engine running.

There's no voltage at the bulb socket.

I confirmed the relays are the same part number before switching them.

There's no black wire coming out of the relays.

Do you have any tips how I can learn about and troubleshoot whether this is an issue with my ECU?

Click to expand...

I'm including info here that I know you've already been through but I would like to leave it for future trouble shooters.

First check and be sure the black wires to your headlamps have continuity to the engine and/or frame. If this ground has been lost the headlamps will not work.
That relay should have one lighter gauge red with yellow tracer wire that supplies the relay coil and one heavier gauge (same color) to the relay input. There will be voltage on these when the key is turned on. The coil wire that is controlled by the ECU is yellow with a black tracer. It should be a lighter gauge wire. Output of the relay to the headlight system will be green. Later in the harness the green wire turns to other colors.
The relay in your pic of the 2 relays on the left is the relay. Measure voltage at the yellow with black tracer wire with the key on only. Don't start the engine. You should see voltage here from the wire with a meter to ground. If there is no voltage check for voltage at the light gauge red w/yellow tracer with the meter to ground. If there is voltage on the red w yellow tracer wire the relay coil is open and should be replaced. If there is voltage on the yellow w/black tracer start the engine.
The voltage on the yellow w/black tracer should drop to zero volts and now the green wire should have voltage.

If the voltage does not drop to zero (Yellow w/ black tracer) either the wire is open to the ECU or the ECU is not pulling the wire to ground. If you trace the Yellow w/ black tracer wire to the ECU and find it is good then the plug at the ECU could be at fault or the ECU is at fault.

If you find the problem is at the ECU we can figure a work-around to get your headlamps working and if needed we can create an un-loader circuit to keep the headlamps off during the starter crank cycle.

Also, you can test the relay coil alone. The relay coil is polarity specific. It has a diode for spike protection to the ECU. Positive goes to the the pin that the red w/ yellow tracer wire and negative goes to the the pin that the yellow w/ black tracer wire. Only do this test unplugged from the bike. You should get continuity between the the heavy gauge red with yellow tracer and the green wire when the relay is energized.

The circuit was designed this way to give the starter more cranking power and is a great design.

On my SV the headlamps come on as soon as the key is turned on but they turn off during the starter crank cycle.

Do you have a schematic for this? If not, someone here can point you in that direction, AS WILL a search!

What Exactly did you do and where did you tap into when installing the grip heaters? Often times if we back up and retrace every step it will reveal what played a roll in the change before you.

FinalImpact said:

Do you have a schematic for this? If not, someone here can point you in that direction, AS WILL a search!

What Exactly did you do and where did you tap into when installing the grip heaters? Often times if we back up and retrace every step it will reveal what played a roll in the change before you.

Click to expand...

Yuuup!

Also just for $h1ts N giggles. Undo your negative cable on your battery for a few minutes. This might undo some logic that got locked. I know generally just volatile memory might reset but try it anyway.

See Attached:

Wow thanks for all the replies! I am sans-garage so will be trying these all these things as the weather allows.

Motogiro said:

Yuuup!

Also just for $h1ts N giggles. Undo your negative cable on your battery for a few minutes. This might undo some logic that got locked. I know generally just volatile memory might reset but try it anyway.

See Attached:

Click to expand...

See unattached. . . hopefully this is the correct half!

WIRING DIAGRAM
FZS6W/FZS6WC EAS28740
1. Main switch
2. AC magneto
3. Rectifier/regulator
4. Backup fuse
5. Fuel injection system fuse
6. Main fuse
7. Starter relay
8. Starter motor
9. Battery
10.Starting circuit cut-off relay
11.Sidestand switch
12.Neutral switch
13.Fuel pump
14.Throttle position sensor
15.Intake air pressure sensor
16.O2 sensor
17.Lean angle sensor
18.Crankshaft position sensor
19.Intake air temperature sensor
20.Coolant temperature sensor
21.ECU (engine control unit)
22.Injector #1
23.Injector #2
24.Injector #3
25.Injector #4
26.Air induction system solenoid
27.Speed sensor
28.Cylinder-#1/#4 ignition coil
29.Cylinder-#2/#3 ignition coil
30.Spark plug
31.Meter assembly
32.Fuel level warning light
33.Oil level warning light
34.Neutral indicator light
35.Tachometer
36.Multi-function meter
37.Engine trouble warning light
38.Coolant temperature warning light
39.High beam indicator light
40.Left turn signal indicator light
41.Right turn signal indicator light
42.Meter light
43.Oil level switch
44.Right handlebar switch
45.Front brake light switch
46.Engine stop switch
47.Start switch
48.Radiator fan motor fuse
49.Radiator fan motor relay
50.Radiator fan motor
51.Signal fuse
52.Headlight fuse
53.Ignition fuse
54.Tail fuse
55.Turn signal relay
56.Rear brake light switch
57.License plate light
58.Tail/brake light
59.Left handlebar switch
60.Clutch switch
61.Dimmer switch
62.Hazard switch
63.Turn signal switch
64.Horn switch
65.Horn
66.Headlight relay
67.Headlight (high beam)
68.Headlight (low beam)
69.Front left turn signal light
70.Front right turn signal light
71.Rear left turn signal light
72.Rear right turn signal light

Any progress on this?

Motogiro said:

Any progress on this?

Click to expand...

It's sunny and 10 degrees today. I'll be having another look before heading off to the Santa Claus parade. I'll let you know what I figure out.

Thank you so much for all the help. I tried disconnecting the negative lead on the battery for a few minutes and it didn't solve the problem so I carried on with the troubleshooting as you suggested.

Motogiro said:

If the voltage does not drop to zero (Yellow w/ black tracer) either the wire is open to the ECU or the ECU is not pulling the wire to ground. If you trace the Yellow w/ black tracer wire to the ECU and find it is good then the plug at the ECU could be at fault or the ECU is at fault.

If you find the problem is at the ECU we can figure a work-around to get your headlamps working and if needed we can create an un-loader circuit to keep the headlamps off during the starter crank cycle.

Click to expand...

The Yellow w/black wire at the relay is not dropping to zero voltage when the engine is running. I can't trace the yellow&black wire to the ECU without unwrapping all sorts of electrical tape which I'm not keen on.

Any last suggestions before I try to workaround?

Is the easiest way to do a workaround is to just connect the green & yellow/red higher guage wires and bypass the relay?

I really have no idea how this happened. At least now I have a spare relay to hook my hand warmers up to next year.

By chance have you disconnected the ECM and looked into the connector? The same is true of all connectors under the tank. It could be corrosion issue specific to a connector.


ECM is top middle:


And this connector here in the rubber housing: Inspect it! Inspect them all!

prock said:

Thank you so much for all the help. I tried disconnecting the negative lead on the battery for a few minutes and it didn't solve the problem so I carried on with the troubleshooting as you suggested.



The Yellow w/black wire at the relay is not dropping to zero voltage when the engine is running. I can't trace the yellow&black wire to the ECU without unwrapping all sorts of electrical tape which I'm not keen on.

Any last suggestions before I try to workaround?

Is the easiest way to do a workaround is to just connect the green & yellow/red higher gauge wires and bypass the relay?

I really have no idea how this happened. At least now I have a spare relay to hook my hand warmers up to next year.

Click to expand...

I would disconnect the battery negative lead.
Unplug the relay.
Unplug the ECU.
Put your meter on 1x ohms range.
Measure for continuity on the yellow with black tracer wire from the relay plug to the ECU plug. If there is continuity the transistor that pulls that circuit to ground is not working in the ECU. If there is no continuity the wire is disconnected either through a harness plug or the wire has been severed.

If there is continuity leave the relay plugged in. Clip the yellow with black tracer wire near the relay. Ground that yellow w/black wire coming from the relay. Your headlamps should now come on when you turn your key on.
You can either ground it to the engine, frame or negative battery terminal.
Make a jumper to test this before you make a permanent connection.

After this has been confirmed we'll make a setup to unload your headlamps during the starter crank cycle.
I'm going to peruse the schematic for a convenient spot to source the crank signal so I can make you an unloader for the headlamps.

There was continuity to the ECU port. I guess somehow it was busted while I was hooking up my grips.

The bike started fine while the headlights were running even though it's been sitting for a month being turned on and off while I've been troubleshooting this. Given that, I don't feel a need to unload the headlamps while it's starting unless there's risk of further damage to the bike. If I had a garage I'd be content to work on it all winter long but I will not be getting enough warm weather or sunlight before the snow starts to take on any further projects. (I'm thoroughly jealous of your San Diego 12 month riding season.)

prock said:

There was continuity to the ECU port. I guess somehow it was busted while I was hooking up my grips.

The bike started fine while the headlights were running even though it's been sitting for a month being turned on and off while I've been troubleshooting this. Given that, I don't feel a need to unload the headlamps while it's starting unless there's risk of further damage to the bike. If I had a garage I'd be content to work on it all winter long but I will not be getting enough warm weather or sunlight before the snow starts to take on any further projects. (I'm thoroughly jealous of your San Diego 12 month riding season.)

Click to expand...

Glad you could figure out what was happening!

Were you able to just ground the yellow w/ black tracer and make it work or did you pull the relay and jump it?

I would still consider building an unloader because you are pulling an extra possible 130 watts that you could be saving. especially with heated grips in the picture. It's pretty simple and very cheap to do!

Yes we are lucky here but we do have winter days where the wind is very dangerous through the passes as we drop into the low desert.

I ran out of daylight. I'm thinking I'll just jump the relay. It seems like removing the relay altogether will make it easier to understand what the wiring is in the future (one less part to untangle).

Actually, I may end up doing both: bypassing the relay for the headlights but also grounding the yellow/black and using that for my heated grips to make sure they shutoff when the bike is switched off. At least then I can tell all my friends that the headlights being on all the time is intentional. XD

Thanks again. It's been a good learning experience (one of the reasons I got into motorcycling to begin with).