Generator Light, Is On Options

[EdwardBlume]

Was driving last week and the generator light came on, went off, came on again, and then it stayed on.

Belt is on, VR was swapped with another I have around (and another is on the way), ground at the tranny is connected and good, battery charged and tightened, fuses 8 & 9 are good and new, spun to make sure they are connected.

Voltage meter is showing 12 to 13.

Anything else I can troubleshoot before I pull the generator? (IMG:style_emoticons/default/dry.gif)

[EdwardBlume]

New alternator, battery, and voltage regulator. Still on... (IMG:style_emoticons/default/headbang.gif)

[Spoke]

New alternator, battery, and voltage regulator. Still on... (IMG:style_emoticons/default/headbang.gif)

So all the electrical components are new and the GEN light is still on?

As mentioned before, if all components are new and the GEN light is still on, then likely you have a wiring issue. The only way to track this down is to measure the system in different points to see if you have the correct voltages.

See the 914 charging system diagram below. It may look complicated but it is quite simple; only 4 components: Alternator, Voltage Regulator, Battery, and GEN light.

Short version of what's going on starting with the alternator. The flux capacitor looking thing in the middle is the STATOR which are the stationary windings and produces a 3-phase AC voltage when running. Above it is the ARMATURE which is a voltage-controlled magnet and is the spinning part. There are 3 banks of diodes, one for each of the 3-phase STATOR windings.

The bottom right bank of diodes is connected to ground and is the return path for current. The top right bank charges the battery. Heavy currents can flow in this path. The top left bank drives the voltage regulator and the left side of the GEN light.

The voltage at alternator pins D+ (top left diode bank) and B+ (top right diode bank) are the same voltage (12.6V to 14V) during operation. When B+ equals D+, the GEN light is out.

Follow the D+ wire from the alternator to the left side of the GEN light. Now follow the B+ wire from the alternator through Fuse 9 to the right side of the GEN light.

In operation, D+ and B+ are the same voltage and the GEN light is OFF. Your GEN light is ON. Do this test:
1) with ignition off, pull the gauge out with the GEN light.
2) Start the car and rev the engine a few times to bootstrap the alternator.
3) Measure the voltage (to ground) on both sides of the GEN light; they should be the same voltage.
4) Write down the voltages and report back on this thread.
5) Depends on what you find in 4). (IMG:style_emoticons/default/beerchug.gif)