bad alternator?

[twizdt]

today i was driving my car and the battery light and brake light came on, and at the same time that happened, my radio shut off.. from my experience this is a bad alternator. well i got home and popped my hood to see if maybe i had blown the alternator fuse due to the slush on the road. well it turns out one of my HID ballasts decided to fall through the intake hole and it got some water between the connections. needless to say, the ballast was fried and stank of burn. Would that cause my alternator to fry? I checked all fuses and they were good. It seemed that leading up to this happening my heat would bog down at idle and my 12v supply would cut out in the car. did my alternator finally take a dump? also when i disconnect the negative on battery the car instantly stalls.

 

[MEz]

Before anything, try tightening the alternator belt. Sometimes when water or oil splashes on the belt, it will tend to slip and not allow for proper charging.

 

[twizdt]

it cant be tightened anymore. its pretty snug

 

[wrencher]

Don't disconnect battery cable as test while the car is running.
That is not a test & proves nothing on our cars.

All you may get out of it is more problems by damaging solid state components.

How about you start with the charging system voltage car running.
If the battery light is constantly on running then the alternator is highly suspect.

 

[twizdt]

i bought a voltmeter today and tested it at the alternator. im getting 11.5v output from the alternator. im confused that how frying my HID ballast finished off the alternator though :/. its 11.5 at the battery and 11.5 at the alternator though. time for new alternator again? haha. good reference on where to get one that will last?

also i have a yellow optima battery.

 

[smokestack]

You could try this

http://www.dsmtuners.com/forums/articles-electrical-wiring/272646-saturn-alternator-swap.html

 

[Desert DSM]

Try this. With the car running, test voltage at the battery posts. Record volts. Then, turn up the stereo and high beams, test voltage. If the alternator can't regulate a consistent voltage (13-14volts) with or without accessories then the alternator is bad. Hope that helps. Good luck man

 

[twizdt]

at the alternator its 11.5 volts same with headlights on. at post the voltage is 11.5 and goes down to like 11.1 with lights on