Issues with charging - voltage drops with rpm
My 98 GSXR 750 doesn't charge the battery. When rpm increase, the voltage goes down. The voltage on the battery is a little higher when the engine is running, than it is when the ignition is off.
This is what I've looked at so far:
- I've measured the resistance of the lead wires coming from the stator, and they all read 0.5-0.6 ohm. Ground test is good, and VAC test from the three leads is also good (~25 vac at idle, 70+ vac at higher rpm).I've opened up the stator housing, and the stator looked fine (I have pictures, but don't know how to upload them). This leads me to believe that the stator is not the cause of my issues.
- I used the diode function on my mulit meter to check the R/R. It gave a consistent reading on all wires, measuring from the positive lead and the negative lead onto all three leads from the stator. Resistance between the positive and negative lead was around 1000 Ohm, and about half of that between the positive/negative and the three leads from the stator.
- I've measured the current directly onto the lead going to the battery. I dosconnected the leads from the battery after starting the engine. This makes the idle rpm rise. I guess the ECU notice the lack of current, and increase rpm in an effort to charge more? Anyway, the current measured at the battery leads is too low (12 and lower), and decrease when with higher rpm. This leads me to believe it's not the battery that is the cause.
- With all connectors pluged in, and the battery connected, I the measured the voltage at the connector from the R/R, by probing it form the backside of the connector. On the R/R side of the connector, the voltage was around 14.4-14.5 when idling. Good right? But it dropped to ~13 when I increased rpm to 5000. I held 5000 rpm for a few seconds, and the voltage continued to drop, about 0.01 volt every second. When measuring from the battery side of the connector, the voltage was a little lower than on the other side. But the voltage was all over the place when I increased rpm. It would jump from 6 volts to 12, and everything in between.
Is that normal? Is the R/R damaged? Is the connector? Is it the harness, or the leads?
Thanks in advance for any help. I'm really at a loss here.
Last edited by Sebbemann; 05-29-2019 at 07:20 AM.