from the 95 shop manual sympton chart for overcharging
- voltage drop in 'A' circuit30 (R)
- voltage drop in 'I', Circuit 15 (GN/BK)
- poor ground
- voltage regulator
- generator
test steps
A1 - check 'A' circuit - ignition to run - measure voltage between (+) battery post and test point A on voltage regulator - is drop less than 0.25V -- if yes go to A2, if no service excess voltage drop in circuit 30 (R). check fuse and connectors in circuit 30 (R) and service as required
A2 - check 'I' circuit - back probe generator connector to measure voltage at wiring harness 'I' terminal, circuit 15 (GN/BK), is voltage less then 1V -- if yes go to A3, if no service high resistance in circuit 15 (GN/BK)
A3 - check grounds - check for poor grounds between voltage regulator and generator, generator and engine, engine and battery, are all grounds clean and tight -- if yes go to A4, if no clean and service grounds as required
A4 - check for field circuit drain - turn ignition to off - measure voltage at test point 'F' on voltage regulator - is voltage at test point 'F' equal to battery voltage (ground voltmeter to case) -- if yes generator ok, replace voltage regulator, if no go to A5
A5 - check for grounded slip ring - remove generator from vehicle - remove voltage regulator from generator - measure resistance from each generator slip ring to the generator housing - is resistance less that 200 ohms -- if yes if grease or dirt has collected near slip ring, clean and recheck, if still less then 200 ohms replace generator, if no replace votlage regulator