Re: [alfa] 14.5 v out of a Spider alternator?????

["Dean W. Cains" <dwc@xxxxxx>]

At 03:40 PM 12/30/2003, you wrote:
> Date: Tue, 30 Dec 2003 07:21:20 -0500
> From: "Mauri and Bob Rand" <r-mrand@domain.elided>
> Subject: [alfa] 14.5 v out of a Spider alternator?????
>
> <<snip>>
>
> Now a couple of questions and please excuse my lack of automotive
> electrical expertise...
>
> Are not the voltage regulators in late model alternators housed
> inside the alternator?  If so, does Vicks have a regulator to
> replace this internal unit?
Yes, the VR is internal, and Vick's adjustable replacement VR is, too.  It 
can be easily installed with the alternator on the engine (2 screws), and 
can even be adjusted with the engine running (1 screw).


> I understand the drain caused by various devices, but will 14.5
> volts output fry any devices sensitive to electricty like the
> ECU, motors, etc.???
The '85 - '88 Alfa Spider factory shop manual spec's 14.5v at the upper end 
of the range, and I've seen 14.7v quoted in manuals for other 
Bosch-equipped cars (BMW & Volvo) I've owned.


> "A fully charged battery should read 12.70 across its terminals,
> and a fully loaded alternator should put out at least 14.5v at
> 3000 rpm."
The same Alfa manual spec's 12.70v as a fully charged battery, 12.48v as 
75% charged, and 12.30v as 50% charged.  I suspect that may vary among 
different battery types, though.  I've often seen 12.72v as indicating a 
full charge in other sources, and my Volvo 850 manual says "12.7v = good, 
12.6v = normal, 12.5v = poor".


> My battery at rest reads about 12.5 and about 13.7 when being
> charged by the engine.  Again will 14.5 cook the battery?
The VR failed on my beater Ford several months ago, and the alternator 
output of 17.5v definitely cooked that battery.  The Ford manual spec's 
"approximately 14 - 15v" as acceptable.

So, you can see that spec's vary, but I feel OK about having the Spider's 
output set at the top of the range, and it really does help the windows, 
wipers, defroster, headlights, etc., operate tolerably well.

As I stated originally, it wasn't just the increased alternator voltage 
that fixed the problems I was having.  The combination of that, along with 
the larger gauge (and additional) B+ cables from the alternator, and 
improved main battery cables, is what really made a difference.

Regards,

Dean


> Thanks,
>
> Bob Rand
> 1987 Alfa Spider Quad Verde
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