I think my alternator is shot - video included
 

I was driving to get my new hood installed (in the rain). I got some water obviously all over my engine. Since then it sounds like my belt is screaming, I can hear a high pitch whine in my stereo and now when I turn on my head lights, my fuel pump makes a terrible sound.

Is it safe to assume I need a rebuild or a new alternator? I tested the voltage, and it was 13.4volts but something is clearly wrong with it.


http://imageshack.us/clip/my-videos/64/5lo.mp4/

That is WEIRD. Are you sure that noise is coming from the back (fuel pump) and not from the alternator or something else?

The fuel pump shouldn't change in pitch - the only thing that could change is voltage going to it, unless it suddenly gets loud with low or high voltage.

See if there's an alternator shop in your town that you can bring them the alt and let them bench test it.

Dale

13.4 volts is OK. What happens to the voltage when the headlights are turned on? Same? Easy enough to pull the alternator and have it tested. Maybe you messed up a relay or the fuel pump resistor/connections under the hood
Read the voltage at the fuel pump without the noise and with, any difference?

I think if you disconnect the belt going to the alternator and start the car you can eliminate the alternator as the culprit if you still have the noise. Also when the belt is off, spin the alternator; it should spin freely and smoothly. You may have a bearing going bad.

As stated above, you should check the voltage going to the fuel pump see if it matches what the FSM says.


John

Let me know if the alternator ends up being bad. I offer rebuilds and high output upgrades. Check the condition of the belt. Also, are you sure thats the fuel pump you head not some interference coming through the stereo? A bad stereo install or poor quality componets may cause all sorts of havoc when electrical loads change. I've never had a fuel pump make noise like that.

It sounds like your voltage pulsation damper may have been damaged. That is what filters electrical noise and prevents the whine in your stereo. Without it you're going to get the whining sound in the speakers that follows the engine speed. Also you get flickers in all the interior lights, and the headlight bulbs might just randomly burn out on their own. They really don't like the noise. It could just be the entire voltage regulator too but unless you scope the alternator you won't really know if it's %100. Sometimes things aren't as black and white as "broken" and "not broken."
If you just want a sure fire solution get a rebuilt alternator. But you could try replacing just the voltage regulator or pulsation damper.

I took the belt off of the alternator and the high pitch squeal under the hood is still there. It might be coming from behind the UIM. Also with the belt off and the lights on the loud screaming still comes from the hatch. I do not think it is the fuel pump now. I think it might be the black things in the picture. Two out of three were extremely hot with only a few minutes of idling. I unplugged one and the sound drastically changed. What are these and what do they do? You can barely see them but while the white connectors are slightly more visible.

http://img109.imageshack.us/img109/1...3000003.th.jpg

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I couldn't tell if the stereo still had whining in it though. 1 neighbor was getting his ducts cleaned and another was cutting the grass.

Bump. Any ideas what the little thing is in the picture?

probably controls the rear wiper washer, which is what that tank is in the picture. another item in the back that can make loud sounds is from the antenna motor.

anyways, the root cause is probably a failed front harness at the LF wheel rubbing through the front main harness. usually that harness has wires rubbed through and when wet will cross feed electricity.

Thought I'd give an update. The noise when I turned on the lights was coming from the rear pump motor. Unplugging it was the band aid solution.

The loud squeal under the hood was because throttle body was sucking in air. Very strange but it went away once it was tightened. Also the boost obviously got MUCH better too lol.