So I installed my LS1 fans and BlackBear harness with a new 130amp alternator finally. Noticed on the way home from my buddies house yesterday it almost whistles like a turbo. I only notice it from about 2500rpms and under. Most noticable after startup or when sitting at a light/stop sign. Checked as soon as I got home and confirmed it was coming from the alternator.

Should I consider sending this thing back ? Tested it out before driving home and it puts out just a little over 130amps at 2200ish rpms reving. Did not have any issues with installing it. Pulley turned freely when spun by hand.


Thanks for the help!

 

It could have a really aggressive fan, but if it sounds like a turbo then most likely bad armature or bearing. What's the voltage under load?

 

Bad bearing gets my vote. You can go to a junk yard and pull a 145 from something, or buy new. I'm assuming that if you bought it new, it's under warranty though.

 

I had the 145 amp for 5 or 6 years and it did have a high pitch scream at below 5 degrees or so. It was weird since the noise was constant during different rpm. I would always forget about it until winter came back. I just went to a 200 amp after the new stereo went in and it hasn't gotten cold yet so I don't know it it still does it. All though it probably never gets that cold there, so it might be another issue.

 

well the noise goes up and down with RPM but cant hear it after about 2000rpms. When idleing in the parking lot with the fan, ac, all lights and stereo up it looks like its right at 14 and some change. If I hold both driver and passenger window switchs up it drops down a little bit. But other then that everything seems to be fine. Its a new 130amp from DB electrical. Doesnt sound like a bearing, just a slight whistle. Cant even hear it when I turn the heat/ac on. Only if the stereo and air is off. But you can hear it from outside.


* Ill try and get a video of it tomorrow after work.