'04 Alternator idle 13.9v - replace?

[geoff]

Should be 14.1v? Full load idle (lights, fog lights, fan, etc) around 13.7v.

Sears tested and said low.

Also are the Bosch/Valeo alternators interchangeable?

 

[KyleT]

yes.

might get it rebuilt for cheaper than a new one though. check around.

A p38 one (for the bosch motor) has a higher output too fwiw.

 

[listerdiesel]

I'd be happy with that voltage, it isn't badly low and allowing for volt drop in the connections is probably withing tolerances.

If you're in a warm climate, charge voltage would be lower to compensate.

Peter

 

[rovercanus]

That doesn't sound bad to me at all. Are you having problems electrically?
13.9 at idle is good. Sears wants your money.

 

[jymmiejamz]

Why did you have it tested in the first place? It could be putting out enough voltage but not enough amps.

 

[jhk07]

My previous alternator did about 14.1/14.2 before it went kaput. Hardly ever saw below 14. I purchased a USED alternator, it now does about 13.7. I have seen lower 13.5/13.4, always starts out at 14.1 ish..... While not jumping for joy, I live with it.


These numbers are scanguge..... hooked up full time.


I don't know what it does, but there is a small gauge wire on back of alternator that you may look at also. I had a friend tell me about it, and sure enough the insulation had hardened and cracked, exposing the stranded copper. I guess that's kind of common.

 

[geoff]

Thanks for all of the comments. It died today running errands over lunch. Battery light came on. I happened to bring my multimeter with me and it showed 12.2v at idle w/AC on.

Ordered a new AL0807N from Amazon. Hopefully it will fit! According to this thread it looks like it should: http://www.discoweb.org/forums/showthread.php?t=76051&highlight=alternator . The mount points for the electrical connections are slightly moved, but doesn't look to be a problem eye balling it.

 

[listerdiesel]

Probably a brush set would cure that, it's about the only thing that fails on the Bosch unit, Valeo aren't quite as good but there are good and bad in all makes.

I carry a set of brushes and bearings for the alternator in a bag in the cubby box, like insurance, you never need it whilst they are there....

Also carry a bearing set for the idlers

Peter

 

[geoff]

The current unit is a Valeo. Lasted 112K miles, although it may have been failing here and there for a few thousand miles prior to being consistently dead. Its been fairly dusty here so the brushes may have gotten beat up. Thanks for the tip on the idlers. I will check those.