New build....alternator not working
 

I'm just finishing a project which I wired completely, but it seems the new alternator is not doing it's job. The battery is a brand new Optima...the wiring is a new Painless system...and the alternator is a new GZ Motorsports, 120 amp racing unit. I wired everything per the Painless instructions. Is it possible that because my battery is grounded at the chassis, rather than directly to the engine block, the alternator will not work properly? The voltage is at 11.5 and dropping with the car running, and all accessories ( water pump, cooling fans, msd ) on. I seriously doubt that I received a faulty alternator from GZ, but anything is possible. I am just about to run a new ground wire from the battery to the engine block...which will be kind of a pain. If anyone has any suggestions before I do this, please let me know. Thanks.

O.k...I'm convinced. It has to be a bad alternator. I ran the grtound to the engine block, and also ran a ground strap from a mounting bolt on the alternator to the block. Checked the ground with a volt meter. It shows good.

Is the alternator a 1-wire type ?? Many of the 1-wire style alternators will not charge at idle, the internal regulator does not receive the proper "excitation" until it is spinning faster. this is especially true when we hotrodders and racers add underdrive pulley systems.

I agree.Underdrive pulley could be cause. If it has normal charge at high RPM you will need to try change the pulley