Alternator Test

[jwmc1]

Can someone walk me through the steps of testing my alternator?

Thanks

[ruf-porsche]

Remove it from the engine.

Wrap it in newspaper or plastic

Open the trunk to a working car

Drive over to Manual-zone or Pep girl, they will test it for free.

[304065]

Sure.

1. Sit in car.
2. Turn key to "On" position. Do not start car.
3. Observe alternator warning lamp on oil pressure gauge.
4. If lamp on, proceed to step eight.
5. VERY carefully remove oil pressure gauge and examine bulb. If bulb filament is broken, replace. If bulb filament fine, test by shorting the side of the bulb holder carrying a blue wire to ground. Bulb should light. Warning: You can easily cause an electrical fire if the wires back there are chafed. If no light, verify that with igniton on, +12v present at other terminal of bulb holder (should be red wire with black stripe). If 12v not present, we have bigger problems.
6. Remove 14-pin connector at electrical console and short MALE blue wire (pin #11) to ground. Bulb should light.
7. Verify continuity of FEMALE pin #11 of 14-pin connector to D+/61 terminal on back of alternator. Alternator will have to be removed to do this.
8. Start car. Alternator warning lamp should go out. If bulb glows softly, this is a problem. Report state of bulb. If warning lamp goes out, good! Now, measure voltage at battery terminals using voltmeter. Voltage should be in excess of 13v.
9. Shut off car. With voltmeter, measure battery voltage. Battery voltage should be 12.5 or so.

Search here for "D+/61" for more details. Good luck!