1992 i4 Camry Alternator Died, replaced it and weird problem?

[bullycanadian]

So yesterday as I was about to drive about 60kms, my battery light came up as I got onto the highway, however luckily i had a new battery in there and luckily again the next exit had a home depot so I was able to park it there and I already had an extra alternator in the trunk which I put in. Now I was able to get a boost and continue my drive back home, but on the highway again with the replacement alternator in my battery light came up again and it died. I got a boost from someone, I also saw that I didnt tighten the negative terminal completely and did that then. Since then its been fine, any idea what would cause the second issue? Could the loose negative terminal cause that?

[chronoti]

yup. with the neg terminal loose it couldn't close the charging loop

[bullycanadian]

Another question I have is don't cars stay running after they have been started and they have their battery dissconnected? Doesn't the alternator provide enought current for the car to stay running? If that is true shouldn't my car have continued to run?