Thoughts on alternator prob

[Ross]

Haven't had much time to think bout this yet, but here it is:

 

Charge warning lights have been very very faintly on in hte ea81t for quite some time - no probs, just ignore.

 

Other day lights all of a sudden came on much more - not completely, but probably 3/4 of their max brightness.

 

Alternator does charge somewhat - but only brings voltage to around 13V with reving the engine - about 12.5V at idle.

 

Brushes are fine.

 

Wiring and grounding are fine.

 

Bad diode maybe?

[subaru_styles]

voltage regulator

[calebz]

voltage regulator

 

Ding!

 

Internal VR - easiest to just replace the alt.

[Ross]

Ahh, sounds good. Cheers guys.

[Bill90Loyale]

And if your battery is getting older (four plus years), you might want to start that new alt with a new battery as well. Bad batteries put a strain on alternators.

[Cougar]

It may be the regulator but I think some of the diodes are toasted. When some open up then you don't get all the normal output. The regulator will try to keep up with the demand but if the load becomes excessive then the voltage goes down. Either way the alternator will need work.

 

I would recommend you get a remaufactured unit from Bosch if you can. You can replace individual parts but others things will still be used inside and will have trouble again later on. If the battery is getting fairly old it is a good idea to replace it also.