Car dies... alternator?

[zero97tsi]

Well, I noticed that my alternator seems to be taking a dive. Turning my headlights on makes my revs dive hard. Anyway, a few days ago I was accelerating and when I let off to shift (from about 5000RPM) the car died when it got to around idle. so ive been watching now and when it get down there it dips really low then goes back to normal, like when the belt winds down it doesnt want to hold the output.

Its done it two more times since that first time and one was on the freeway this morning.

Does this sound like Im blaming the right part?

 

[95CarbonEclipse]

I'd double check for any loose battery terminal connections first. Especially the ground cable.

 

[weldtuner]

If you know how to use a dmm or digital multi meter, check to see what voltage you are charging at idle and at a higher rpm, at least above 3k, where the alternator really starts to supply full power. Check what the ground resistance is( with car off) from your alternator case to battery ground( alternator is case ground). I added a additional ground wire at the alternator and noticed another .2 volts at idle. Good luck

 

[92awddsm]

Check for boost/vacuum leaks, proper iac function, and readjust idle speed.

 

[mrtalon40]

Well, I noticed that my alternator seems to be taking a dive. Turning my headlights on makes my revs dive hard. Anyway, a few days ago I was accelerating and when I let off to shift (from about 5000RPM) the car died when it got to around idle. so ive been watching now and when it get down there it dips really low then goes back to normal, like when the belt winds down it doesnt want to hold the output.

Its done it two more times since that first time and one was on the freeway this morning.

Does this sound like Im blaming the right part?

it could be a vacuum leak! Is the car just go completely dead and no power? or just shuts off? if it keeps going dead and you will have to keep giving it a jump but still wont help thats your alternator bad cause then you were running the car off straight battery, if not the cars shuts off you have you a vacuum leak buddy they kinda annoying to find but its an easy fix though

 

[zero97tsi]

I'm going to go the route of vac leak right now. I tested the alt and its in tip top output, and yes, it just shuts off, the oil press light comes on and all the other lights that come on when the car isnt running but on. I almost freaked out the first time it died since I can't tell it's not running from sound and I saw all those lights

Any way, im getting code "P0170 Fuel Trim Bank 1" now, so I'm sure it has something to do with that because it wasn't throwing that before it started dieing.