my alternator will work then shut off, like all the time, but mostly when the headlights are on.
like ill jump start it, and all the lights will be lit up strong, and i can go pull a terminal and it will be running off the alternator, but then i could turn on my headlights and about 5 minutes later all the lights will start pulsating, and then when i kill it, and try to start it the battery is dead, and if i jump it without the headlights it will start up fine and the alternator will be working but if i start it with the lights on and try to pull a terminal off and my car will die.
so i think somewhere the headlights short out the alternator but idk where i would start to chcking for that. any ideas? lol

 

also, i swapped the d16y7 to the d16y8, with wiring harness and ecu

 

Load test the battery, replace if weak, replace the battery ends if they are jacked up, most are, and fix your engine grounds. You are bound to have at least one that you forgot to reinstall. IN THE CORRECT LOCATIONS

Headlamps have nothing to do with the alternator other than that they use power.

 

Tested the battery, replaced. Tried 3 different ones, all my grounds are tight and in the right place and I understand that headlights done effect the alt at all, but the alternator only shorts out and stops working when the healights are on

 

First of all, do you even know what shorting out means? Second, you have a ground problem. Fix the ground. I'm nearly 100% certain that is your problem, I've seen this type of problem more than once.

 

alright ill start on that tomorrow,
and also, my car is always idling at around 2000 rpms (i dont have a tac) and it is hitting rev limiter when it should be hitting vtec, any advice?