Scenario :
• New battery
• Not recharging
• Self is not working
• Other electrical components such as meter lights, pilot lamp, horn, indicators are not working.
The first thing what we do is replacing the old battery with the new one. But before replacing, we have to check several other factors. Let's see them one by one...
Checking the Self motor ( Not compulsory )
Firstly, try to self start the bike. If you hear the sound from self relay but the self motor is not working, then you have to check the wiring of self motor circuit. If everything is fine, dismantle the self motor and check the carbon brushes. Replace the carbon brushes with the new one if necessary.
Check for the recharge voltage
Set the multimeter to DC20 or DC200. Place the probes in the battery terminals. If your bike is having a kick start mechanism, use them to start and slightly rev your engine. Your recharge voltage should be in the range of 13 - 14.3 volts. When your battery recharge voltage is fine and still your accessories and self doesn't work, you have to look after the wirings, fuse and sockets going for accessories. If your battery is not recharging you have to proceed with further steps.
Check the coil voltage
Now a days, all the motorbikes are fitted only with pickup coil and lightning coils. Here, the voltage produced from lightning coils are used for lightning purposes and for battery recharging. The voltage produced here is AC voltage. For converting it into DC and to regulate it, RR unit(Regulator & Rectifier) is used. If the voltage produces here is low, then the battery won't recharge. This is called as magneto unit and it is placed in the left side of your engine case.
We have to find the wires coming from this lightning and battery recharge coil. For that, we have to know some basic color codes. Mostly, the positive line wire is in white color. In some Bajaj bikes, it'll be in blue and some in yellow. The negative line or neutral line will be in green color and black in some other bikes. Firstly, you have to disconnect the socket from lightning and battery recharge line. Because, if you check the voltage without disconnecting the socket, the voltage shown in the multimeter will become wrong in case of faulty RR unit. So, it is always best to disconnect the sockets and check the voltage.
Set the multimeter to AC 200, disconnect the sockets and place the meter probes in the respective positive and neutral lines from battery recharge and lightning coil. Start your bike. At medium revving condition, the voltage produced should be in the range of 35 - 70. It may vary from bike to bike. The maximum voltage produced here will be up to 140 volts. If you didn't receive the voltage, then there might be problem in your coil assembly. If everything is fine, then proceed with the next step.
( After starting the bike, disconnect the positive terminal from the battery. The vehicle should not turn off. If the vehicle is turned off, then surely the problem will be in the RR unit )
Check the wiring from coil assembly to RR unit
Set your multimeter to continuity mode. Set one end of the probe in positive line from coil socket and another end in the end of that wire which is located in the RR unit. If you hear the beep sound, the connection is good. Follow the same procedure for negative line also. If you didn't get the continuity, check the wirings. If everything is good, proceed with the next step.
Check for input voltage in the RR unit
As we know earlier, some amount of voltage will be produced in the coil assembly. These voltage will be directly guided to the RR unit. Set the multimeter to AC200 and place the probes in the respective input terminals (from coil assembly) of the RR with plugged in. Start the bike and check for voltage. If very low voltage is shown in the meter, switch of the bike and remove the socket from the RR unit. Now fix the probes in the inputs from coil assembly wiring socket and start the bike. If we receive the same voltage produced in the coil assembly, then the fault is in the RR unit. When the input socket is plugged in and when the RR unit is shorted, the input voltage will not enter into the RR unit. That's the reason for the very low voltage shown in meter when the input socket is plugged into the RR unit. The problem will be rectified when we replace the old RR unit with the new one.
• New battery
• Not recharging
• Self is not working
• Other electrical components such as meter lights, pilot lamp, horn, indicators are not working.
The first thing what we do is replacing the old battery with the new one. But before replacing, we have to check several other factors. Let's see them one by one...
Checking the Self motor ( Not compulsory )
Firstly, try to self start the bike. If you hear the sound from self relay but the self motor is not working, then you have to check the wiring of self motor circuit. If everything is fine, dismantle the self motor and check the carbon brushes. Replace the carbon brushes with the new one if necessary.
Check for the recharge voltage
Set the multimeter to DC20 or DC200. Place the probes in the battery terminals. If your bike is having a kick start mechanism, use them to start and slightly rev your engine. Your recharge voltage should be in the range of 13 - 14.3 volts. When your battery recharge voltage is fine and still your accessories and self doesn't work, you have to look after the wirings, fuse and sockets going for accessories. If your battery is not recharging you have to proceed with further steps.
Check the coil voltage
Now a days, all the motorbikes are fitted only with pickup coil and lightning coils. Here, the voltage produced from lightning coils are used for lightning purposes and for battery recharging. The voltage produced here is AC voltage. For converting it into DC and to regulate it, RR unit(Regulator & Rectifier) is used. If the voltage produces here is low, then the battery won't recharge. This is called as magneto unit and it is placed in the left side of your engine case.
We have to find the wires coming from this lightning and battery recharge coil. For that, we have to know some basic color codes. Mostly, the positive line wire is in white color. In some Bajaj bikes, it'll be in blue and some in yellow. The negative line or neutral line will be in green color and black in some other bikes. Firstly, you have to disconnect the socket from lightning and battery recharge line. Because, if you check the voltage without disconnecting the socket, the voltage shown in the multimeter will become wrong in case of faulty RR unit. So, it is always best to disconnect the sockets and check the voltage.
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| Layout of coil assembly |
Set the multimeter to AC 200, disconnect the sockets and place the meter probes in the respective positive and neutral lines from battery recharge and lightning coil. Start your bike. At medium revving condition, the voltage produced should be in the range of 35 - 70. It may vary from bike to bike. The maximum voltage produced here will be up to 140 volts. If you didn't receive the voltage, then there might be problem in your coil assembly. If everything is fine, then proceed with the next step.
( After starting the bike, disconnect the positive terminal from the battery. The vehicle should not turn off. If the vehicle is turned off, then surely the problem will be in the RR unit )
Check the wiring from coil assembly to RR unit
Set your multimeter to continuity mode. Set one end of the probe in positive line from coil socket and another end in the end of that wire which is located in the RR unit. If you hear the beep sound, the connection is good. Follow the same procedure for negative line also. If you didn't get the continuity, check the wirings. If everything is good, proceed with the next step.
Check for input voltage in the RR unit
As we know earlier, some amount of voltage will be produced in the coil assembly. These voltage will be directly guided to the RR unit. Set the multimeter to AC200 and place the probes in the respective input terminals (from coil assembly) of the RR with plugged in. Start the bike and check for voltage. If very low voltage is shown in the meter, switch of the bike and remove the socket from the RR unit. Now fix the probes in the inputs from coil assembly wiring socket and start the bike. If we receive the same voltage produced in the coil assembly, then the fault is in the RR unit. When the input socket is plugged in and when the RR unit is shorted, the input voltage will not enter into the RR unit. That's the reason for the very low voltage shown in meter when the input socket is plugged into the RR unit. The problem will be rectified when we replace the old RR unit with the new one.
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| Layout of RR unit |
Post check
After installing a new RR unit you have to crosscheck. In previous case (with faulty RR unit), the input voltage will be very very low when the input socket is plugged in. After installing a new one, we have to check the voltage when the input socket is plugged in. The voltage produced in the magneto coil assembly should be shown in the RR unit's input. After checking that, check the output voltage from the RR unit. Set the multimeter to DC20. Make sure that sufficient amount of voltage is coming from the RR unit to recharge the battery.
In most of the cases, RR unit will become faulty. But we have to make sure that all the system responsible for the battery recharging is working fine. Assume that the RR unit is also working fine and still your battery is not recharging. Then you have to check for the output line wire from the RR unit and make sure the continuity is present until the end of the wire. Then you have to check for the rust in the battery terminals.
After rectifying all the problems, your battery should recharge. By revving, the maximum voltage of 14.5 will be shown in the meter(DC20), while the probes are in contact with the respective battery terminals. Firstly, headlights and meter lights will not work. After rectifying the problems, make sure that all the lights, horns and other accessories are working properly.
( After rectifying, try to remove the positive terminal from the battery. The vehicle should not be turned off. By performing this activity, you can make sure that the RR unit it working fine )
After installing a new RR unit you have to crosscheck. In previous case (with faulty RR unit), the input voltage will be very very low when the input socket is plugged in. After installing a new one, we have to check the voltage when the input socket is plugged in. The voltage produced in the magneto coil assembly should be shown in the RR unit's input. After checking that, check the output voltage from the RR unit. Set the multimeter to DC20. Make sure that sufficient amount of voltage is coming from the RR unit to recharge the battery.
In most of the cases, RR unit will become faulty. But we have to make sure that all the system responsible for the battery recharging is working fine. Assume that the RR unit is also working fine and still your battery is not recharging. Then you have to check for the output line wire from the RR unit and make sure the continuity is present until the end of the wire. Then you have to check for the rust in the battery terminals.
After rectifying all the problems, your battery should recharge. By revving, the maximum voltage of 14.5 will be shown in the meter(DC20), while the probes are in contact with the respective battery terminals. Firstly, headlights and meter lights will not work. After rectifying the problems, make sure that all the lights, horns and other accessories are working properly.
( After rectifying, try to remove the positive terminal from the battery. The vehicle should not be turned off. By performing this activity, you can make sure that the RR unit it working fine )