Finally got good enough weather and time to poke around the electrics of my Pan last weekend to see what could be causing the charging issues. Having removed enough covers to see the actual alternator, it seems there are 3 cracks in it . Before condemning the whole unit though (it never actually seized or showed any other symptoms) I decided to probe the battery with volt and ammeters. What I found was slightly surprising. Before taking these measurements, the battery was fully charged:
First of all, without the headlights on, the voltage across the battery terminals was:
@idle (~800RPM) 11.7V
2000RPM 13.5V
3000RPM 14.1V
With headlights on full, the voltage dropped:
800RPM: 11.37V
2000RPM 11.65V
3000RPM 11.75V
Unfortunately, the voltage on the rear terminal of the alternator was similar so I don't think it's a connection issue.
I next disconnected the 55A alternator fuse and connected an ammeter across the connections. This is what I found: With the ignition on and the engine not running, 2.74A flowed into the alternator. Is this the current to energize the stator coils? It seems rather large to me. Disconnecting the 10A alternator/starter circuit fuse and measuring the current through this circuit (ignition on, engine not running) showed just 0.25A flowing after the fuel pump cut out. I thought this would be the path for energizing the stator but maybe I misunderstood the wiring diagram.
After starting the engine, the current across the 55A fuse connections was:
idling 800RPM: 0.3A from alternator
2000RPM 6.8A
3000RPM 9.7A (with headlights turned on).
It seems pretty clear that the alternator is failing, but does this sound like the R-R or the alternator itself? I wondered if anyone could comment on the 2.7A current draw through the alternator with the engine off.
Also do I still need to pull the swingarm etc. to test the regulator etc. or are there any further checks that I could carry out to confirm if it's the R-R or the alternator itself at fault without removing anything.
Any help or advice would be appreciated.
Gareth
First of all, without the headlights on, the voltage across the battery terminals was:
@idle (~800RPM) 11.7V
2000RPM 13.5V
3000RPM 14.1V
With headlights on full, the voltage dropped:
800RPM: 11.37V
2000RPM 11.65V
3000RPM 11.75V
Unfortunately, the voltage on the rear terminal of the alternator was similar so I don't think it's a connection issue.
I next disconnected the 55A alternator fuse and connected an ammeter across the connections. This is what I found: With the ignition on and the engine not running, 2.74A flowed into the alternator. Is this the current to energize the stator coils? It seems rather large to me. Disconnecting the 10A alternator/starter circuit fuse and measuring the current through this circuit (ignition on, engine not running) showed just 0.25A flowing after the fuel pump cut out. I thought this would be the path for energizing the stator but maybe I misunderstood the wiring diagram.
After starting the engine, the current across the 55A fuse connections was:
idling 800RPM: 0.3A from alternator
2000RPM 6.8A
3000RPM 9.7A (with headlights turned on).
It seems pretty clear that the alternator is failing, but does this sound like the R-R or the alternator itself? I wondered if anyone could comment on the 2.7A current draw through the alternator with the engine off.
Also do I still need to pull the swingarm etc. to test the regulator etc. or are there any further checks that I could carry out to confirm if it's the R-R or the alternator itself at fault without removing anything.
Any help or advice would be appreciated.
Gareth