Puzzled.

[Limeyrider]

Working my way through the electrics on a 1985 VMax, pressing the START button causes the starter relay ( above the battery ) to click, and lights to dim. Following the troubleshooting pages in the Yamaha manual, the manual instructs " check battery voltage on R/B lead " , voltage should be 12v, I get 8.9 v. Connecting the B/Y lead to ground does nothing, apparently the relay unit should click. The unit that is shown in the manual is marked for flashers and hazard warning ... the unit has the marking 41R-71 .... can anyone confirm that this is the correct unit?. Of all of the connections on the left side of the bike, this is the only unit with the mentioned colour coded wiring. In addition, the front turn signals remain lit with the main switch turned to "ON", they will flash when the turn signal switch is operated. Thanks for any, and all advice.

 

[02GF74]

I don't understand the problem.

Are you saying pressing starter dims the headlamp and starter relay clicks (is correct operation) but the engine is not turned over by the starter?

I don't understand why the flasher relay is mentioned, that has nothing to do with the starting.

What condition is the battery?
Are the connection to the battery clean and tight?

If the problem is not starting (starter motor not turning the engine over), has it ever started or turned over.?

If yes, what was changed?

 

[Limeyrider]

Pressing the starter dims the lights.....but does not turn the engine over.
I was also puzzled by the inclusion of the flasher relay ... the troubleshooting page in the manual, page 7- 8 in the electric starting section shows a dark photo that appears to be the flasher relay .... and the flasher relay is the only unit with a R/B wire ...mentioned in the testing text
The battery is new ... and fully charged. Connections are tight.
The bike is a project that me and my son are working on ... we have NOT heard the engine running, when we picked the project up, the seller used jumper leads from his truck battery connected to the bike battery ( not the new one ), the engine turned over, all that has changed is the bike location.... and the fitting of a new battery.

 

[02GF74]

All that has changed is the bike location.... and the fitting of a new battery.

We can rule out the change of location as the cause.

Is the battery connected the right way round? And of at least the same Ah capacity as OEM?

Now that may sound a stupid question but there have been 2 occasions posted on here when it wasn't - I don't remember the details but in one case the main fuse kept blowing on pressing the starter, in the second it didn't. For both, the bike did not run and luckily no electrical components were damaged.

BTW do you hear the vboost motor cycle when the ignition is turned on?

 

[Limeyrider]

The battery is connected .... Red leads attached to red + terminal, Black lead attached to - terminal.
I can hear the v boost motor cycle when the ignition is turned on.
BTW ... the oil indicator light lights up when the Start button is pressed ??.

Thanks for your input.

 

[MaxMidnight]

The '85 has a combined starter circuit cut off and indicator relay and is located under the LH scoop and is correct for the model.
The starter relay is located under the seat.
The front indicators have running lights so would be on and flash when indicating.
The oil and fuel level lights should come on when the starter is pressed and shows that the bulbs are working.

You have disconnected the blue/ white connector from the starter relay and get 8.9v?
If so that is where you need to start your diagnosis.
What is the voltage measured at the battery? Anything below 12.6 v means the battery isn't fully charged, less than 10v it is discharged.

As the bike turned over when jumped that suggests that the starter circuit is working as it should and that the most likely issue is that the battery is Donald Ducked or needs charging.

 

[Fire-medic]

What is the voltage measured at the battery? Anything below 12.6 v means the battery isn't fully charged, less than 10v it is discharged.

As the bike turned over when jumped that suggests that the starter circuit is working as it should and that the most likely issue is that the battery is Donald Ducked or needs charging.

" the battery isn't fully charged"-that sounds like the culprit, given the reading mentioned by the O.P.

" the most likely issue is that the battery is Donald Ducked"-reports of my demise have been greatly exaggerated.
(signed)
D. Duck

 

[Limeyrider]

The '85 has a combined starter circuit cut off and indicator relay and is located under the LH scoop and is correct for the model.
The starter relay is located under the seat.
The front indicators have running lights so would be on and flash when indicating.
The oil and fuel level lights should come on when the starter is pressed and shows that the bulbs are working.

You have disconnected the blue/ white connector from the starter relay and get 8.9v?
If so that is where you need to start your diagnosis.
What is the voltage measured at the battery? Anything below 12.6 v means the battery isn't fully charged, less than 10v it is discharged.

As the bike turned over when jumped that suggests that the starter circuit is working as it should and that the most likely issue is that the battery is Donald Ducked or needs charging.

Hi MaxMidnight .... My apologies for the delayed reply.
I disconnected the blue / white wire from the starter relay and got 12.8 volts. The 8.9 volts was measured at the red / black wire in the combined starter circuit cut off relay ... the manual states 12 volts ??.
The battery measures 13.7 volts across the terminals .
Only the oil warning lamp glows when pressing the starter ... the fuel indicator my be a blown bulb.
The next step will be to use jumper cables connected to a known good battery and see if the engine turns over, an automotive parts shop can perform a battery test to determine internal condition i.e. duff cell.
Thanks for clarifying the front indicator condition !.

The '85 has a combined starter circuit cut off and indicator relay and is located under the LH scoop and is correct for the model.
The starter relay is located under the seat.
The front indicators have running lights so would be on and flash when indicating.
The oil and fuel level lights should come on when the starter is pressed and shows that the bulbs are working.

You have disconnected the blue/ white connector from the starter relay and get 8.9v?
If so that is where you need to start your diagnosis.
What is the voltage measured at the battery? Anything below 12.6 v means the battery isn't fully charged, less than 10v it is discharged.

As the bike turned over when jumped that suggests that the starter circuit is working as it should and that the most likely issue is that the battery is Donald Ducked or needs charging.

 

[MaxMidnight]

The 8.9 volts was measured at the red / black wire in the combined starter circuit cut off relay ... the manual states 12 volts ??.

In that case the manual goes on to say 'Check for an open or poor connection between the main switch and relay unit'.
Sounds simple but this wire goes from the relay to the start switch to the fuse (red/ white) to the ignition switch (brown).
I'd start checking in reverse order from the ignition switch. If you are still getting 8.9 v then you need to check back to the main fuse and battery.
To clean the connections all you need to do is to remove the connector from the component, make sure the connectors are tight and not burned and then replace and remove the multi blocks several times.
Can we assume that all of the earth points have been taken apart and cleaned?

The battery measures 13.7 volts across the terminals.

The only time I would expect to get that reading is after the motor had been running or the battery had recently been on charge.
If that was the case then you need to let it rest for a couple of hours or leave the lights on for several minutes to remove the surface charge.

 

[Limeyrider]

Hey MaxMidnight .... thank you for your reply.
The battery was on fresh charge when I measured the 13.7 volts, drops to 12,6 after resting.
The earthing points have not yet a) been located, b) not cleaned.... that will be the task for today. If the 8.9 volts persists then checking in reverse order will be done .... starting with the main switch. Thanks again.... much appreciated.

 

[putin]

Hey MaxMidnight .... thank you for your reply.
The battery was on fresh charge when I measured the 13.7 volts, drops to 12,6 after resting.
The earthing points have not yet a) been located, b) not cleaned.... that will be the task for today. If the 8.9 volts persists then checking in reverse order will be done .... starting with the main switch. Thanks again.... much appreciated.

Maybe something draining battery. I had something like this, after cold night can not start the bike. I bought Odissey battery and that is ok now.

 

[Fire-medic]

The earthing points have not yet a) been located

 

[Limeyrider]

Maybe something draining battery. I had something like this, after cold night can not start the bike. I bought Odissey battery and that is ok now.

Hey putin .... the battery seems to be holding the charge ok, doesn't appear to be draining.

 

[Limeyrider]

View attachment 85415

Hey FireMedic .... thanks for the photo .... that helps ... and may answer a question !.

 

[Limeyrider]

View attachment 85415

Following the engine ground cable up .... there is a lighter gauge wire coming out of the ground cable almost at the upper terminal end .... where does that attach to ?.....and where does the engine ground cable cable attach ?.... there is no apparent attachment point for either the main ground cable, or the " spur " wire .

 

[MaxMidnight]

With the seat off the main eath point is approximately where the arrow points.

 

[Limeyrider]

Thank you MaxMidnight .... the main earthing point may be in a different location on the project bike .... IF the main earth cable is the one coming from next to the oil filler it will not reach to the seat area , I'll check for evidence of attachment to the frame.

 

[Limeyrider]

These four wires ... one is the heavier cable from the engine earth ... don't appear to have a near connection point ....any idea's will be appreciated. The engine earth cable terminal is a bit difficult to see, the red coloured wire ( shrink tubing ) comes out of the sheathing from the engine earth.

 

[Limeyrider]

This is becoming aggravating ... voltage between the main switch and the main fuse = 9.9 volts, continuity test is good.

 

[02GF74]

It is not easy to diagnose problems at a distance without knowing what is being done or what experience with car/bike electrics the person has.

Firstly, when checking continuity, either with an analogue or digital voltmeter, the bike battery shoujld be disconnected at poistive. The way the meters work is by appliing a voltage (they have an internal battery), then measuring the ucrrent (or vice versa) in order to calculate the resistance. If there is another voltage wource in the circuit, then at best the value measured is wrong, at worst the meter gets damaged.

To measure voltages, the negative (black lead) of the meter should be against ground, the negative terminal of the battery.

Going back to post 1.

check battery voltage on R/B lead " , voltage should be 12v, I get 8.9 v.

In the wiring diagram, the red/black lead originates from the engine stop switch to the starter circuit cut off relay.
The starter swith is fed by red/white wire from the ignition 10 Amp fuse, which is connected by brown wire to the igntition switch.

What is the voltage on the following: (trracing power from battery all the way to the igniton relay)
1. red wire igniton swith
2. brown wire ignition switch
3. fusebox brown wire
4. 10 A fuse with red/white wire
5. ignition stop switch red/white wire
6. as above, red/black wire
7. red/black wire at ignition relay

... but in your last photo, I can see one red lead, one thick black lead (is this the engine ground as pointed out by Maxmidnight?) and 2 black wires floating in mid air - these need to be connected correctly.