Persistent Engine Noise

I just came in from doing the check. sorry for the delay there... There was no noise at all with the power cables disconnected from the alt. Everything sounded good.

In response to your last question, I did with the truck running but the saturn off. I figured that would be the a way to tell if it was the car's alt or not b/c the battery's juice would be coming from the truck's charging system and not the car's. I did not do it with the truck off and the car running though. Do I need to do that at this point?

It was a whine that I got that changed with the RPM of the car. I just happen to have a PGold 1/2 F cap not being used. I may be able to find a place to squeeze it in by the alt. I would figure the closer, the better, but what's an ideal distance... or would it matter? Since the battery is in the trunk (OEM location), I have a cable running from the alt to the trunk and a lot more room to mount back there. I also have a cable running from the frame of the alt to the negative battery post and then to the frame there too so the ground is easily accessable. Will this do or is that too far?

Replacing the alt versus having the rectifiers replaced... either way can be costly on a tight budget. Since it is an 07 model car, the stator and bushings and all *should* be fine in the alt... but so should the rectifiers!

The closer the better, but if you hook the truck back up and with the saturn running you have no noise, the truck battery is the capacitor.  If it helped or eliminated the noise and it is easier to do it at the battery, try it there.  It should do a little better near the Alternator.

I'll do that and will repost hopefully tomorrow evening. It's getting late here and I am in the middle of preparing dinner, taking care of other things. Look for an update soon.

Thanks a lot to for the help thus far! 7 pages of material here and this is really the first point that something of substance is coming up. Thanks also the12volt. I guess 7 pages was the point that an admin says "enough" and steps in! lol

I appreciate it and will update soon.

well... no luck. I installed my half-farad phoenix gold cap but there was no change in anything.

what next?

If you added some grounds to the factory system try disconnecting them the only thing I can think is that you created a ground loop.  Also is there a computer mounted to the vehicle floor?  If so try isolating it from the chassis of the car.

I am only 3.5 hours away from you with an air conditioned shop.  More than willing to try and get it fixed for you.

To my knowledge, I am not aware of any additional grounds to the factory system, except for the ground cable run from the alternator housing to the negative post on the battery and to the frame but that was way at the end of my struggle and did not impact anything with the noise. I think what I am going to do is take everything out and start over, piece by piece... reinstalling everything again, one single item at a time. Like I said, I'm not aware of any ground loops anywhere but that doesnt mean none exist.

Where are you located? you can reply in a PM if you care to. If I cant get it this go around, I may just take it to you though time and money are critical points.

Was there anything out of the ordinary with the results from the AC voltage test? You mentioned also that you wanted me to have the jumper cables connected from my truck to the saturn but the truck not running and the saturn running. I can do this still, if you think it will help diagnose an issue. What should I expect to occur?