I have a 2000 GSR with only a few mods (I/E/H, OBD1 ECU) and my voltage of the entire car fluctuates. It happens when the car is wamed up. Often it is linked to RPM or acceleration but not 100% of the time.

When the RPM is high, the voltage of the entire car is around 13.7 - 14V. When I'm at idle or in neutral, it is around 11.6 - 12V. But again, the fluctuations don't always correlate with this.

IDEAS ANYONE???

 

Test voltage at batt. posts, should be 12.5V, engine not running, 13.5V engine running, up to 14.5V engine RPM up.

Do the same tests with meter pos.(+) probe on batt. post and neg.(-) probe on cars chassis, [studs ob shock tower], if voltages are diff. check the main grounds, batt., batt. to chassis, chassis to engine.

Most batt./alt shops will to a batt./alt./charging, [load] test for free, it only takes a few min. 94

 

Thanks, I'll try all of those ideas out.