Alt.

I got 2 3g 200 amp alt in my car but i cant figure out how to hook them up, what am i sopose to do with the white wire on the second alt. and the plug on the second alt.

Hook the same wires to each other, that would be parallel. I thought the 3g alts were single wire alts? Meaning the are chassis grounded.

2 alternators of that amperage? but why?

run a google for mustang 3g alternator installation and you'll come up with some great walk throughs.

do these alternators have regulators on the back, which have 3 wire hookups? i'm not sure about this, but i believe you can get another regulator plug from another mustang/EEC-IV car and wire it in parallel with the stock one... the same applies to the white stator wire. i'm no electrical engineer, so i don't know if parallel regulators will work properly... hopefully somebody else on here is more knowlegable than i.

they are chassy grounded but it seems like the second one is not working, that is why i thing it has to do with the white wire and the plug

Have you tried to see if they work independently?

yes they both work