12v DC bike not running

[bernardgreen]

Normally the charging socket has a switch that operated when the charger is plugged in. The switch disconnects the battery from the motors when the charger is plugged in. This prevents the charger from being connected the motors. This is necessary because the load from the motors may be too great for the charger and running motors from the charger may over load and damage the charger,

I think this is most likely

The yellow is the Positive feed to the motor control PCB and motors
The red is the Positive to and from the Battery.
The black is the negative to the Battery and the PCB.

Without the charger plugged in the yellow is connected the red in the socket thus battery Positive is connected to the PCB

When the charger is plugged in then the yellow is disconnected from the red thus the motor control PCB is disconnected from the battery and charger.

 

[dabomb3k]

When you say yellow and black connected at charger socket do you mean just connected to there corresponding sockets or physically touching each other like when I'm testing it off the mains..

I will double check what you said when I get home this evening just to rule it out completely..

Thanks a lot for your help so far

 

[JohnW2]

Normally the charging socket has a switch that operated when the charger is plugged in. The switch disconnects the battery from the motors when the charger is plugged in. This prevents the charger from being connected the motors. This is necessary because the load from the motors may be too great for the charger and running motors from the charger may over load and damage the charger, I think this is most likely
The yellow is the Positive feed to the motor control PCB and motors
The red is the Positive to and from the Battery.
The black is the negative to the Battery and the PCB.
Without the charger plugged in the yellow is connected the red in the socket thus battery Positive is connected to the PCB ... When the charger is plugged in then the yellow is disconnected from the red thus the motor control PCB is disconnected from the battery and charger.

Indeed, that has all been discussed. The only difference is that flameport, who seemed to be conversant with these things, asserted that that yellow was connected to the black (presumably battery negative), not the red, when the charger plug was removed. This seems consistent with the OP's finding that the motor will run (presumably off the charger) if the charger is plugged in and the yellow and black are linked together.

Kind Regards, John

 

[JohnW2]

When you say yellow and black connected at charger socket do you mean just connected to there corresponding sockets or physically touching each other like when I'm testing it off the mains..

I meant that the yellow and black should be physically (electrically) joined together at the socket (which is what flameport indicated would be happening within the socket,, when the charger was not plugged in, if the socket was not faulty) - i.e. just as a means of bypassing any fault in the 'switching' which should be happening within the socket.

Kind Regards, John

 

[bernardgreen]

There are embossed labels on the PCB case next to the wires. Can you tell us what these are as this will ( should ) make it clear what each wire does.

Are there any labels on the socket ? this would help to identify the socket and thus work out what each of the terminals does.

Also make and model of the bike would help to find a service manual or circuit diagram.

The separation of motor from battery during charging is most often by disconnecting the Positive but as you mention linking black to yellow allows the motors to run then the separation may be in the Negative line.

 

[dabomb3k]

I'll have to answer some of the questions when I'm home but the make model: it's the bike at the following address: http://m.fun4kids.co.uk/rocket-cruiser-deluxe-ride-on-12v-electric-motorbike-red.html


The embossed letters I will need to give u later also but I know that some of them are :

VCC
POWER
RAMOT
GND

 

[dabomb3k]

Hi guys, I have followed your instructions to test the voltage off the battery to the pcb which is 12v

I have also tested the voltage going off the pcb to the motor when I am pressing the foot pedal and I am not
Getting any voltage to the motor nor am I getting a drop in voltage off the battery either, however I am getting 12v off the pcb going to the on/off switch on the bike on the VCC connector (the red wire that is linked into the on off button and also the dc charger port)

The embossed labels on the pcb at that point are:

VCC. red lead (connected with the dc charger and towards on/off switch)
POWER. Orange
RAMOT. Green
GND. Yellow. (Connected to the dc charger socket)
F. Blue
B. White
ANT. Unused

 

[bernardgreen]

I know that the red is obviously positive, black negative shut Im unsure what the purpose of the yellow lead is.. I think the charger socket maybe faulty as the yellow and black cable should be connected at the socket and when I put metal across them it completes the circuit? Is this correct...

Never assume that black is negative,

The negative from socket to the PCB and battery is the Yellow.

The Black from the charging socket is a negative supply to the controls. When the charger is plugged in the Black is open circuited to remove the Negative from the controls to prevent the bike being operated on the charger.

If the batteries charge when the charger is plugged in ( a slight increase in battery voltage when the charger is connected ) and the bike runs normally on the battery when Black and Yellow are linked ( charger unplugged ) then 99% certain the contacts ( Black to Yellow ) in the socket have failed and are not closing when the charger plug is removed.

Either a new socket or add a switch to link Black and Yellow and ensure it is turned OFF when the charger is plugged in. It won't matter if it is turned OFF when the charger is unplugged, that will only dis-able the controls as if the charger was plugged in.

 

[dabomb3k]

Okay thanks. Just to clarify as I think we may have crossed wires (no pun)

The only way I can get the unit to work Id by switching the black wire into the yellow wires socket at the charger and then plugging the charger in , the whole bike , all buttons and functions then work

If I try this without the charger plugged in then I can't get it to power up at all even if I link out the black and yellow wires or connect all 3 to a standard toggle switch I still get nothing

 

[JohnW2]

If the batteries charge when the charger is plugged in ( a slight increase in battery voltage when the charger is connected ) and the bike runs normally on the battery when Black and Yellow are linked ( charger unplugged ) then 99% certain the contacts ( Black to Yellow ) in the socket have failed and are not closing when the charger plug is removed.

IF your "ifs" were correct, then that would be true, and was one of the first suggestions made in this thread. However, as I understand it, the bit of the above I have highlighted is not correct - AIUI without the charger plugged in, the bike will not work, even if the OP links black and yellow at teh socket.

Either a new socket or add a switch to link Black and Yellow and ensure it is turned OFF when the charger is plugged in.

As above, my understanding is that, following out suggestions, the OP has tried that and it does not work.

Kind Regards, John

 

[dabomb3k]

That is correct john I think, did you see my above post where I tested the things you mentioned yesterday? Still no luck..

 

[JohnW2]

That is correct john I think, did you see my above post where I tested the things you mentioned yesterday? Still no luck..

I confess that I had missed that post from you - but, unfortunately, it doesn't seem to move us forward! Do I take it that you tried those tests with the yellow and black connected together at the charger socket, and with the on/off switch 'on'?

When you say you are getting 12V on the wire going to the on/off switch, what are you measuring relative to? There is presumably another wire coming back from the switch (is that perhaps the orange?) - if so, what voltage,if any, are you seeing on that?

I fear that, sooner or later, we are probably going to be left, by default, with thinking that something must be wrong within that 'PCB' housing.

Kind Regards, John

 

[dabomb3k]

Hi john, I was measuring the vcc line off the pcb with my red lead and then I was putting the other lead on the black line of the battery (not sure my thought process on that just assumed positive and negative)

Unfortunately I also cannot be certain which other wire goes to the on off switch as it is housed in the main casing of the bike that I don't have access too, I can try and have another look this evening but whati can see is that the conectors VCC POWER GND etc go off to a connector point that then heads to the on off switch, the foot pedal and also the power for the auxilleery port and the LED lighting on the front of the bike..

The only questionable thing I have about it being a pcb failure or indeed a component failure is that if that's the case then why does it all work (including the motor) when I run it off the charger (charger plugged in and black line switched)

Also in answer to your question when I tested yesterday, i physically put a link between the black and yellow at the socket to bypass the switch

Finally.. A mate of mine has a multimeter that can test dc current he tells me
So I'll borrow that off him and see if I'm getting any current off the battery when i press the buttons.. I'm guessing I shouldnt expect too many Amps...

 

[JohnW2]

Hi john, I was measuring the vcc line off the pcb with my red lead and then I was putting the other lead on the black line of the battery (not sure my thought process on that just assumed positive and negative)

That's fair enough.

The only questionable thing I have about it being a pcb failure or indeed a component failure is that if that's the case then why does it all work (including the motor) when I run it off the charger (charger plugged in and black line switched)

It really depends upon what goes on in that 'PCB' (are you sure it's a PCB inside that housing?). If it includes switching into 'battery mode' when the charger is unplugged, then failure of that functionality could obviously result in what you're seeing. I'm certainly not saying that there is definitely a problem with the 'PCB'- merely that we may eventually be left with nothing else to point a finger at!

Finally.. A mate of mine has a multimeter that can test dc current he tells me ... So I'll borrow that off him and see if I'm getting any current off the battery when i press the buttons.. I'm guessing I shouldnt expect too many Amps...

That really won't help. If the motor isn't running (and if no volts are getting to the moror), there will be no, or virtually no, current flowing out of the battery - and we know that without doing any measurements. Whatever you do, don't connect a meter on its current range across the battery (or between any other two points which have voltage between them) - that would probably kill the meter, might kill the batteries and could harm you!

I don't think anyone has actually asked you - do we take it that this bike did once work 'as intended' and, if so, do I take it that nothing 'happened' which might possibly explain the change from working to not working?

Kind Regards, John

 

[bernardgreen]

It might be that the battery connection has failed inside the module. Maybe a fuse on the PCB board has blown and the battery is effectively disconnected.

Can you monitor the voltage on the battery terminals and then plug the charger in, If the charger is working then the voltage on the battery should increase slightly.