1991 3g alternator not charging

[AeroCoupe]

Have you checked the voltage at the battery (meter to the positive and negative terminals)? If not do so and then move the red meter lead over to the battery post on the alternator and the black meter lead to the case. You should get the same voltage within a tenth or two. This will indicate if the case is grounded or not.

Best way is to do a voltage drop test to ensure that the alternator case is grounded and your connections are good.

 

[BigShowJoe]

Have you checked the voltage at the battery (meter to the positive and negative terminals)? If not do so and then move the red meter lead over to the battery post on the alternator and the black meter lead to the case. You should get the same voltage within a tenth or two. This will indicate if the case is grounded or not.

Best way is to do a voltage drop test to ensure that the alternator case is grounded and your connections are good.

Yeah I went down that road early on.

 

[Blown88GT]

...Other than that mine is wired just like that diagram.

Got everything installed and wired without using the original black/orange power wires, and I get no charge with the engine running....

That diagram above is incomplete.

If you removed these wires, it will not charge. You also need to connect the stator post on the 3G to the "S" terminal on the regulator. See wiring diagram in attached file.

 

[Chuckster101]

1991 LX hatch with F.A.S.T ECU, MSD ignition and distributor, HCI, Vortech V1.

The original 75 amp 2g alternator quit charging and I took the opportunity to upgrade to a 3g 130 amp kit from LMR.

Got everything installed and wired without using the original black/orange power wires, and I get no charge with the engine running. I verified continuity from the alternator post with the new 4 gauge power wire back to the battery positive terminal. I have 12v constant on the yellow wire. The white wire is connected from the middle of the D plug to the stator plug as it should be. The green/red wire is suspect though. With the key off, it has 0 volts which is expected. With the key on but engine stopped, it has 12v, also as expected. The strange thing is that with the engine running and D plug disconnected from the alternator, that green/red wire is fluctuating in volgate. Never below 12v but my meter reads 12v, 16v, 14v, and even a spike to 20v for a moment.

I can only assume that is the reason behind no charge from the alternator since that wire doesn't have constant voltage but I need input from you all. What can cause voltage on that green/red wire to jump around like that? Failing ignition switch sending power through that bulb/resistor circuit?

Maybe I’m missing something? You took out the fusible link from the blk./org. Wires ? That’s a no no !