Why alternator goes bad so soon?

[Learning]

Hi

I had my alternator (made by American Motor Parts) replaced 2 months ago and now it's not charging. Before that, the alternator was a Bosch and lasted only 1.5 years.
What could have caused them to have such short lives? Could it be caused by the alternator belt itself such as wrong tension ? Or could it be caused by not grounding the alternator correctly ? Is it really imperative to ground an alternator correctly?

[Balleristic31]

Why wouldn't you be grounding it?

[Dj Buttchug]

shitty grounds can cause all kinds of problems, and yes a poor ground can cause premature failure.

The M42 engine is not grounded very well as it is from the factory. Some large gauge grounds really help alot. I would suggest testing all the factory grounds, and adding some of your own

[Learning]

Why wouldn't you be grounding it?

A mechanic replaced the alternator for me. I don't know if he did ground the alternator correctly or not. From reading I found it's essential to ground an alternator properly. I don't know much about engine which leads me to this question: what's the difference between an engine block and an engine chassis? From what I've read it's said we should ground an alternator to the engine chassis and not to the engine block.

[oldmann]

You CAN ground to the block, IF your engine block has a GOOD ground to the frame (chassis).

Run an 8 guage ground wire directly from the alt. to the frame, no more ground issue.