NC30 electric issue

[krisztian_andre]

Could you be more specific, which points are connected to where exactly. IMO the minimum earth connection upgrade is the addition of a direct link between the -ve battery terminal and the chassis. The OEM design does not appear to have one, does your bike have such a connection?

Measure the voltage directly at the output terminals of the rect/reg, do you get a reliable 14.0 - 14.5 volts at this point.

Earth wires from frame earth point to coils, starter motor and the regulator.

Main worry is why are my voltages at the battery decrease as the engine speed increases, it should be the other way around!

It sounds like your regulator and or genny is broken.

Have you done electrical tests on it yet? There simple standard tests to get the output of the bike.

Can you explain the last one in this list:

- battery at 12V and would not charge to higher voltage.
- rectifier connectors were very corroded, cleaned that up
- the resistance between the alternator wires was 0.6, 0.6 and 0.9 ohm which is nominal
- my earths are fine, earth upgrade was recently installed and I cleaned up all the connectors except for the rectifiers
- battery and rectifier were replaced a year ago
- wiring loom is in a bad condition
- measured the resistances of the rectifier and they are all nominal except between the yellow(alternator) connectors where the resistance was infinite (spec is 30k-500k ohm)
- strange thing was that when I recharged the battery (still only 12V on the terminals) and started the bike I actually measured a lower voltage on at a higher rpm: 14V@1200rpm and 13V@4500rpm at the battery terminals.

[magg]

Battery voltages will reduce with increased engine rpm if the -ve return path from the rect/reg resistance is too high. This is a consequence of the way Honda has arranged the wiring loom. I would add that other manufactures use similar methodology which results in the same problem.

If you get more than 14 volts at the output of the rect/reg then the charging system is ok. Less than this voltage at the battery is because of the losses through the wiring loom. An earth wire from the -ve terminal of the rect/red to chassis is one way to improve the situation. An earth wire from the rect/reg mounting screw to chassis will have no effect.

[krisztian_andre]

Made some more measurements:

- voltage at the output terminals of the regulator(red and green I think) at 4800rpm with the battery not connected to the regulator was an amazing 1V
- voltages between the alternator output wires when disconnected from the regulator at 4800 rpm were 40V, 40V and 37V

[krisztian_andre]

Battery voltages will reduce with increased engine rpm if the -ve return path from the rect/reg resistance is too high. This is a consequence of the way Honda has arranged the wiring loom. I would add that other manufactures use similar methodology which results in the same problem.

If you get more than 14 volts at the output of the rect/reg then the charging system is ok. Less than this voltage at the battery is because of the losses through the wiring loom. An earth wire from the -ve terminal of the rect/red to chassis is one way to improve the situation. An earth wire from the rect/reg mounting screw to chassis will have no effect.

You're probably right about the regulator housing not being connected to its - pole.
My voltages decrease with the engine speed because according to the measurement of 1V on the regulator I'm effectively running a total loss system.
What I still don't understand is that why do I get 14V across the battery terminals on idle and 12V when disconnected if my regulator doesn't supply any current to the battery.

My regulator is garbage and my only option at the moment is to hit the junkyard and find an alternative there. I've heard R6 regulators with 5 connectors are good, what else would fit?

[magg]

The rect/reg should have remained CONNECTED to the loom while measuring its output. With the rect/reg NOT connected to a battery it will not function correctly and the output is effectively AC not DC, were you trying to measure AC or DC?

[krisztian_andre]

The rect/reg should have remained CONNECTED to the loom while measuring its output. With the rect/reg NOT connected to a battery it will not function correctly and the output is effectively AC not DC, were you trying to measure AC or DC?

I measured DC and the alternator was connected to regulator of course just not to the battery.
Regulator may not be broken then?

So measure AC at regulator output while everything connected.

[magg]

Measure DC at rect/reg output red and green wires with everything including battery connected.

[krisztian_andre]

I borrowed a better multimeter from a friend and measured

- 14V-at the battery at 5000rpm
- 43V, 43V and 40V on the alternator at 5000rpm
- 12.8V at the battery, ignition off

[krisztian_andre]

This issue is solved it seems.
Replaced rectifier connector and connected the green wire going to the rectifier directly to the frame earth point and replaced the battery(died after a year due to undercharging).
Now I'm getting 14.6V at the battery at 5000rpm :)

[magg]

I should correct my earlier statement

With the rect/reg NOT connected to a battery it will not function correctly and the output is effectively AC not DC, were you trying to measure AC or DC?

I should have said

With the rect/reg NOT connected to a battery it will not function correctly and the output may be only 1-2 volts or narrow pulse DC that cannot be measured by a multimeter.