Alternator

[paulv]

Checked some repair specs for the 2001 Outback alternator:

(1) Voltage of the alternator output should be 13.5v at 900 rpm
(2) Current output:
18A at 1250 rpm
49A at 2500 rpm
58A at 5000 rpm
(3) Voltage Regulator:
14.3 to 14.8v at 5000rpm.

The service info also stated that the VR is part of the alternator but is a serviceable part.

HTH.

Regards,
paul...

[mikehkang]

Originally Posted by paulv

Checked some repair specs for the 2001 Outback alternator:

(1) Voltage of the alternator output should be 13.5v at 900 rpm
(2) Current output:
18A at 1250 rpm
49A at 2500 rpm
58A at 5000 rpm
(3) Voltage Regulator:
14.3 to 14.8v at 5000rpm.

The service info also stated that the VR is part of the alternator but is a serviceable part.

HTH.

Regards,
paul...

Thanks for the info Paul.
Clearly something is wrong with mine. My output is barely over 12v.

[paulv]

Originally Posted by mikehkang

Thanks for the info Paul.
Clearly something is wrong with mine. My output is barely over 12v.

In addition to the VR, the rectifier could be hosed causing the overall average voltage you're reading to be low.

I don't know about an 01 Outback (as I just bought an '10 Forester and it's my first Subaru), but the VR and diode rectifier for my model have separate part numbers for purchase (if you don't mind pulling the alternator apart!).

Before you tackle this job, I suggest that you take the alternator to someplace to test it (as gschotland recommended) so you don't change parts that are working fine.

Regards,
paul...

[yimmy149]

Driving the car a dozen miles once a week is probably murder on your battery - depending on how much parasitic drain the car has when parked. Charging systems in cars are meant to keep the battery topped up, not charge it from near flat. I would get a battery maintainer for it.

[mikehkang]

Originally Posted by yimmy149

Driving the car a dozen miles once a week is probably murder on your battery - depending on how much parasitic drain the car has when parked. Charging systems in cars are meant to keep the battery topped up, not charge it from near flat. I would get a battery maintainer for it.

It is unfortunate for the Subi that it has to compete with the Boxster for driving time.

[mikehkang]

I took gschotland's suggestion and took the alternator to Autozone for test.
It failed.

While I was removing the alternator, I checked the belt and it was really bad - the burning smell was coming from the alternator's pulley and the belt contact. I didn't know it at first but the black powder on the alternator's side that faces the pulley was from the belt!

The best news is that I think I discovered WHY I have had problems with my alternators. My theory is that the belt's tension was too tight. My Subi has adjustable tension bolt. I am about a good half inch lower than where it was and now the tension seems just right. (I really need a better way to tell tension. Any suggestions?) If I were to set the adjustable tension bolt to how it was, there is almost no give in the belt.

My guess is that all the previous "paid" mechanics didn't bother to really check the belt's tension but always restored to the tension bolt's previous and wrong setting.

My lession?
1. The collective knowledge of this forum is invaluable.
2. If you want the job done right, you have to do it. Or, at least you should have an idea so you would know if the job was done properly.

Thank you for all you input.

P.S. My gadget is happy too. I do get the "alternator bad" sign when I idle AND turn on the A/C, but I can live with that.

Here is the picture of my gadget.