I am a bit confused... are you referring to the same test as scottly, wherein I am unplugging the 2 field coil wires and testing the resistance between the white and green wires connected to the field coil (like in the picture)? I thought I was looking for it to read 0L for open line.
I am having a hard time getting a good clean reading as it changes constantly depending on where the probes touch the bullet tip of the wire. Maybe they need cleaning? Also I’m not sure if this matters but with the key on there is plenty of magnetism to hold a paper clip to the casing of the stator.
Thanks!
Andy
I'm thinking you may be more than a bit confused. I don't want to speak for Scottly. Maybe you'd prefer to wait for his response.
Of course you clean the bullets....AND the sockets! Corrosion is resistive and increases the measured resistance! The only alternative is to pierce the corrosion coating with a very pointy probe. That will gain you a better measurement possibility. But, unless you clean the corrosion coating, it won't help alternator function in circuit.
IIRC, On the 550, there is only one wire available that reaches from the field coil to the regulator, the White wire. The green wire at the regulator attaches to the frame/motor and the field coil has its functionally "green" wire attached to the motor case.
The field coil is exactly that. A coil of wire with two ends. One is connected through bullet style connectors under the drive sprocket cover. Yes, that one can become resistive, also. So check it.
The "logically green" wire of the field coil connects to the green at the regulator via the motor case -> to frame -> to the harness green wire connection. If the motor isn't electrically connected to the frame (think paint insulation), the regulator can't properly drive the alternator field coil.
If you expect the alternator/regulator to do their job, the regulator must "see" a field coil load of ~4.8 ohms at its terminals, not 10 ohms.
So, either correct the connectivity between field coil and regulator, or measure the field coil as near to the field coil proper and determine it is actually 10 ohms (proven failure) or 4.8 ohms (which would prove your issue is elsewhere than the coil itself).
And finally, if your test equipment is lying to you, you aren't ever going to make any sense of this issue. So, take steps as outlined previously, to gain confidence that your measurements aren't further confusing the resolution of your charging troubles.
Carry on...
