Charging system

[omnislash]

Hi everyone,

 

I had a bit of prob with my batt recently. Suspecting my charging system to be faulty, I measured my charging voltage at 5000rpm and found it to be 12.9V, a big diff from what my manual says it ought to be, at 14V.

 

Knowing the fuse is good, i went to the next step to measure the resistance of my stator coil. I measured at the coupler thats connected to the rectifier. It gave me 0.6 ohms at room temp say 30 deg C.

 

The manual says it should be 0.15-0.23 ohms at 20 deg C when measured directly from the coil side.

 

Is my coil the cause of the poor charging?

[omnislash]

No one knows?

[Aalex82]

No one knows?

 

maybe not much ppl use this method to check for coil..

one of the common practice is

use a multimeter or juz a light bulb to check for reading between the 3 wires coming from the coil..

as for honda bikes, mostly is 3 yellow wires..

wire A, B, C..

red wire of meter go A and black wire to B. then red to A and black to C..

check all possible combination and there should be reading

hope this help..

[omnislash]

maybe not much ppl use this method to check for coil..

one of the common practice is

use a multimeter or juz a light bulb to check for reading between the 3 wires coming from the coil..

as for honda bikes, mostly is 3 yellow wires..

wire A, B, C..

red wire of meter go A and black wire to B. then red to A and black to C..

check all possible combination and there should be reading

hope this help..

 

Thanx for the reply. Mine is 3 white wires. And I checked the combi like what you described. Its just that I checked the resistance between the coils instead of the voltage generated with the engine running. Is that what you are asking me to do?

[Aalex82]

Thanx for the reply. Mine is 3 white wires. And I checked the combi like what you described. Its just that I checked the resistance between the coils instead of the voltage generated with the engine running. Is that what you are asking me to do?

 

yup..

but by checking resistance of the 3 wires thru diff combination, based on the formula i learnt, if the resistance is higher than the stated value, the coil can be consider faulty..

u oso hav to check for continuity of each of the 3 wires wif grd.. there should not be any continuity..

[omnislash]

Ok. Just did a little research and also told me to check for continuity with ground. Didn't do it the last time round. Got to take out fairing all over again. I just hope the extra wire bridging the rectifier with the coil is not the cause for the jump in resistance resulting in wrong judgment of coil condition. I mean engineering knowledge tells me it shouldn't, its just that i cant be 100% sure.

[Aalex82]

Ok. Just did a little research and also told me to check for continuity with ground. Didn't do it the last time round. Got to take out fairing all over again. I just hope the extra wire bridging the rectifier with the coil is not the cause for the jump in resistance resulting in wrong judgment of coil condition. I mean engineering knowledge tells me it shouldn't, its just that i cant be 100% sure.

 

how the extra wire bridge from coil to the rect??

normally is bridge from rect to batt..

the extra wire will reduce the current in the oem wire..

[omnislash]

how the extra wire bridge from coil to the rect??

normally is bridge from rect to batt..

the extra wire will reduce the current in the oem wire..

 

What i meant was the wire that transfers the electrical power from the coil to the rectifier. Cuz I was suppose to measure the resistance AT THE COIL. But due to accessibility, I had to measure at the rectifier side (before rectifier)... So there is this extra resistance that comes from the "bridging" wire right.... Just that it shouldn't add that much resistance i tot...

[Aalex82]

What i meant was the wire that transfers the electrical power from the coil to the rectifier. Cuz I was suppose to measure the resistance AT THE COIL. But due to accessibility, I had to measure at the rectifier side (before rectifier)... So there is this extra resistance that comes from the "bridging" wire right.... Just that it shouldn't add that much resistance i tot...

 

the checking is on the socket end where u attach the rect together wif the coil..

is not opening up the engine cover to access the coil itself..

resistance from the bridging wire can consider as insignificant..

[omnislash]

the checking is on the socket end where u attach the rect together wif the coil..

is not opening up the engine cover to access the coil itself..

resistance from the bridging wire can consider as insignificant..

 

Yea... Cuz my Manual ask me to open the engine cover and measure from the coil directly which I thought is pretty stupid. That's why I measured from the socket. But I couldn't get the spec of the manual.

 

Thanx for confirming my thoughts. But den, my multimeter I think cannot measure up to such a small resistance. The smallest scale is up to 20 ohms. I tried measuring a copper wire and it gave me 0.6 ohms as well. CCB... I'll try to measure the AC voltage now. It should be 50VAC right?

[omnislash]

I've just checked the stator coil o/p:

 

Phase 1 - phase 2 => 21.5 VAC

 

Phase 1 - phase 3 => 15.0 VAC

 

Phase 2 - phase 3 => 0.6 VAC

 

The shitty thing is, all the coils have continuity to ground!!! ALL read ~0.8 ohms to ground!!!

[Aalex82]

I've just checked the stator coil o/p:

 

Phase 1 - phase 2 => 21.5 VAC

 

Phase 1 - phase 3 => 15.0 VAC

 

Phase 2 - phase 3 => 0.6 VAC

 

The shitty thing is, all the coils have continuity to ground!!! ALL read ~0.8 ohms to ground!!!

 

looks like yr coil really up the lorry le..

need to find a replacement le..

[omnislash]

Thanx Aalex82 for all the info.

 

I've managed to replaced my coil le... Phew... Now the charging system is back up again.

 

Thank you again for all the help rendered.