Puzzled.

[Limeyrider]

Hey 02GF74 .... thank you for the tutorial ... something learned !.
My auto electrical experience is limited to simple wiring on old British bikes .... no relays etc.
I will check the voltage at the area's indicated in your posting.
In my last photo ... the "red lead" is actually black with red shrink tubing applied to cover and insulate chafed wire,that wire comes out of the heavier cable sheathing. The heavier black cable is the engine ground ... I don't see where the upper end terminal will attach ?, the two lighter gauge wires " floating in mid air " were unattached when we picked the bike up ... I have no clue as to where those two wires attach ... they have brass terminals ... as for connecting correctly ... again ... no clue as to where they attach .... pinching all four of those wires / cables together causes the headlight to brighten ??. Thank you for your input.

 

[Fire-medic]

pinching all four of those wires / cables together causes the headlight to brighten ?

Yes, because you have a good ground! Connect them to the frame for the seat latch or for the thick one, by the oil ("710") cap.

 

[Limeyrider]

Ah... that makes sense, the seat latch is in a cardboard box ! .... hopefully, connecting those wires properly will get me closer to the goal ...a starter motor that will operate !. Thank you for the photo's and your observation. The lower end of the heavier cable is connected next to the oil filler cap.

 

[Fire-medic]

Ah... that makes sense, the seat latch is in a cardboard box ! .... hopefully, connecting those wires properly will get me closer to the goal ...a starter motor that will operate !. Thank you for the photo's and your observation. The lower end of the heavier cable is connected next to the oil filler cap.

Yep, let us know when you have it operational. Poor/no grounds won't allow you to enjoy your ride.

 

[02GF74]

Firemedic beat me to it. Generally on cars and motorcycles, there is a ground loom, rather than using the steel chassis or frame as the ground. Steel is a relatively poor conductor of electricity and rusts which can degrade the contacts. That's why for example you have a 2 wires to indicator bulbs instead of one and using the frame ad the ground.

So first step is to connect those wires so they are not floating. The two with eyelet connect together via the bolt, and to the frame.

The large one, is likely a ground connecting to the battery or another point that connects to the battery.

Only after those leads, and any others are connected and still no start should you chase the voltage at the points mentioned as that is quite time consuming.

 

[Limeyrider]

Yep, let us know when you have it operational. Poor/no grounds won't allow you to enjoy your ride.

Thank you Fire-medic ... hopefully, and very soon, I can report success !. Thanks again .

 

[Limeyrider]

Firemedic beat me to it. Generally on cars and motorcycles, there is a ground loom, rather than using the steel chassis or frame as the ground. Steel is a relatively poor conductor of electricity and rusts which can degrade the contacts. That's why for example you have a 2 wires to indicator bulbs instead of one and using the frame ad the ground.

So first step is to connect those wires so they are not floating. The two with eyelet connect together via the bolt, and to the frame.

The large one, is likely a ground connecting to the battery or another point that connects to the battery.

Only after those leads, and any others are connected and still no start should you chase the voltage at the points mentioned as that is quite time consuming.

Hey 02GF74 .... as I said previously, my experience with auto electric is limited to older, British bikes, typically earthed to the frame tubing. I will be sure to gather up the loose ends, clean and re attach to the indicated points, hoping for success ... or at least more progress !. Thanks for your time and input.

 

[Vmaxstreetfighter]

If all of that fails ... I had very strange issues with a gen 1 including some of your symptoms and also the engine running on 2 cylinders for the first 2 minutes on start up. We chased the issue around for a year, with new parts including rectifier/battery (which made the bike run better but didn't solve the problem). Then I replaced the turn signal relay and it was all sorted. No one could explain why!

 

[Limeyrider]

Hey Vmaxstreetfighter, the old Brit bikes may not have been as advanced (???) as the modern day stuff, but they sure were / are a great deal easier to diagnose and to fix .... at the roadside !.Thanks for the heads up.

 

[MaxMidnight]

Hey Vmaxstreetfighter, the old Brit bikes may not have been as advanced (???) as the modern day stuff, but they sure were / are a great deal easier to diagnose and to fix .... at the roadside !.

True but they still worked on the same electrical principle i.e. A feed out the the various circuits and then (usually) earthed through a single point on the frame and then back to the battery.
The Max needs the additional engine earth as this is rubber mounted which most Brit iron wasn't.
As far as diagnosis is concerned you need to work through in a logical manner but always start with the basics - good connections and continuity from one side of the battery to the other.
Until that checks out OK I wouldn't worry about the the components.

 

[hnmisousa1]

Assuming the output of the battery/voltage regulator is 12v, voltage drops mean high resistance.

 

[Limeyrider]

True but they still worked on the same electrical principle i.e. A feed out the the various circuits and then (usually) earthed through a single point on the frame and then back to the battery.
The Max needs the additional engine earth as this is rubber mounted which most Brit iron wasn't.
As far as diagnosis is concerned you need to work through in a logical manner but always start with the basics - good connections and continuity from one side of the battery to the other.
Until that checks out OK I wouldn't worry about the the components.

Hey MaxMidnight .... I am beginning to attempt to check each circuit, but I am REALLY puzzled by the engine earth cable, it is connected close to the oil filler cap, but does not have sufficient length to attach to ANY frame component. The photograph that I posted showed the engine earth having a " pig tail " attached .... I assumed that it is a factory piece ?, there are two other wires " out in mid air ", I am able to connect those two, and the engine earth " pig tail " to the seat locking bracket .... but the main engine earth cable remains unattached ???. Another revelation ... I did not know that the engine is rubber mounted !. Thank you for your time and input .... much appreciated.

 

[MaxMidnight]

If memory serves well (which it may not) the other end of the heavy cable goes to the -ve terminal of the battery and the pig tail to the common frame earth.
I'm sure others will correct me if I have that wrong.

 

[Limeyrider]

Hey MaxMidnight .... I have managed to get the engine earth cable connected to the battery -ve terminal, the pigtail is bundled with the " flying " wires.
Following are the voltage measurements :
Red wire at the ign. switch ...12.6 volts.
Brown wire are ign. switch.... 0 volts ( zero).
Ign. fuse ( 10A.) ... 9.9 volts R/W wire.
Engine stop switch ...R/W wire 10.8 volts
Engine stop switch ... R/B wire ..10.6 volts.
Ign. relay R/B wire .... 9.8 volts .... operating the switch gives a reading of 10.2 volts. , moving the R/B wire causes a " crackling " sound inside the relay body ???
Something amiss .... but so far, beyond my ability to locate.

 

[MaxMidnight]

Yep, definitely something wrong...
I'm assuming you are taking the measurements with the switch on? I also assume you have a wiring diagram?
If you have 12.6 (battery) voltage at the feed (red wire) into the switch and 0v at the brown (output) then you won't (shouldn't) get a reading at the fuse as it is this wire that feeds the fuse block.
Also 9.9v at the ignition fuse increases to 10.8 at the stop switch seems wrong to me; I'd expect a voltage drop not increase.

Next step I'd do would be to investigate the ignition switch internals to see what is causing the voltage drop.
What voltage do you get at the fuse if you bypass the switch and bridge the red and brown wires?

 

[02GF74]

Following are the voltage measurements :
Red wire at the ign. switch ...12.6 volts. = good; power from the battery via the main 30A fuse
Brown wire are ign. switch.... 0 volts ( zero). = no; if ignition switch is turned on ,this connects main power to fuse box; all electrical components hang off this via 4 fuses; includng the starting circuit. you should be measuring 12.6v as above
Ign. fuse ( 10A.) ... 9.9 volts R/W wire. = no, this can't be right; the ignition 10 A fuse is fed by the brown wire above, which you have measured as 0 V?!??!?!?
Engine stop switch ...R/W wire 10.8 volts = no, this connects to 10 A igniton fuse so should be same voltage as above.
Engine stop switch ... R/B wire ..10.6 volts.
Ign. relay R/B wire .... 9.8 volts .... operating the switch gives a reading of 10.2 volts. , moving the R/B wire causes a " crackling " sound inside the relay body ???
Something amiss .... but so far, beyond my ability to locate

I suggest you measure voltage at brown wire at ignition swith when igniton is turned on again.

If it is still 0v, then you need to take the ignition switch apart as the contacts or not working.

oops .... just seen MM is saying the same thing.....

 

[Limeyrider]

Yep, definitely something wrong...
I'm assuming you are taking the measurements with the switch on? I also assume you have a wiring diagram?
If you have 12.6 (battery) voltage at the feed (red wire) into the switch and 0v at the brown (output) then you won't (shouldn't) get a reading at the fuse as it is this wire that feeds the fuse block.
Also 9.9v at the ignition fuse increases to 10.8 at the stop switch seems wrong to me; I'd expect a voltage drop not increase.

Next step I'd do would be to investigate the ignition switch internals to see what is causing the voltage drop.
What voltage do you get at the fuse if you bypass the switch and bridge the red and brown wires?

Hey MaxMidnight ... thank you for your reply ...and patience ...
Yes, the switch is ON, I have the " official " Yamaha manual with wiring diagram ( it is like showing a Chinaman the London underground map ! ).
Bridging the RED and BROWN wires I measured 11.4 volts.
There appears to be a problem with the flasher relay , there is a crackling sound at times ... and the starter relay stops clicking ???.
The ignition 10A fuse has two wires feeding it ... neither are brown, both wires are RED / WHITE, the Brown wires appear to be feeding the FAN fuse ??.

 

[Limeyrider]

I suggest you measure voltage at brown wire at ignition swith when igniton is turned on again.

If it is still 0v, then you need to take the ignition switch apart as the contacts or not working.

oops .... just seen MM is saying the same thing.....

Hey 02GF74 ... see my reply to MM above. Thanks .

 

[Limeyrider]

Update ! .... I re measured the voltage at the Brown wire at the ignition switch ... getting better contact ... turned the switch ON and measured 11.4 volts , and 12.5 volts on the Red wire .

 

[02GF74]

You may want to remove the headlamp bulb as that is draining the battery when ignition is on, no harm leaving it I it just buys you more time as you investigate before needing to charge the battery.

According to the manual, the pre 1990 models have a combined flasher and starter inhibitor unit, this has 9 wires 2 of which are blue/white. I assume this is the module making the cracking sound.

I would suggest unplugging the unit.

Once the unit is unplugged, touch the blue/white wire to ground at the starter solenoid, engine should spin round.

Then connect both the blue/white together at the plug - I would expect female blade connectors so poking in a small wire would so it.

Pressing the stater should turn the engine over, and it should run.


Basically the unit I said to unplug deals with 2 functions.

1.flash the indicators and auto cancelling them - we're not interested in that right now
2. Safety circuit that takes wires from various components to inhibit starting the engine.

There is a blue/white wire going in, this is grounded by the ignition switch.

If all safety conditions are met the unit will pass the ground on the other blue/white wire that connects to the starter solenoid , that will start the engine.

The crackling noise would imply something is not right inside the unit.