[DeTomaso] is my alternator dying? (no direct P content)

[doug351c]

At 2000 RPM and above, you should always have between 13.7 and 14.3V at the
battery.  Since you're seeing less than this voltage, take your alternator
to a local auto parts store.  Most of them will test it for free.  If your
alternator checks out OK, buy a new regulator.  If that doesn't fix it, you
have a wiring problem.

Doug Braun
blue 73L #5505

-----Original Message-----
From: detomaso-bounces at realbig.com
[mailto:detomaso-bounces at realbig.com]On Behalf Of Pantdino
Sent: Saturday, January 08, 2011 5:46 PM
To: detomaso at realbig.com
Subject: [DeTomaso] is my alternator dying? (no direct P content)

I'm having a problem with the charging system in my Dino-- namely that it
shows slight discharge even at 3000 rpm without the lights on.
Anyone know enough about charging systems to tell me if my alternator is
dying?

Suffice it to say I think the coil, ignition box, and rev limiter are all
OK-- there is no huge amp drain that could be making a charging condition
impossible. There is no significant current flow unless the ignition is on.

Today I did some measurements on the terminals at the voltage regulator,
which I will repost here in hopes of getting advice:

I checked the voltage regulator outputs again--
With the new regulator from Fiat Plus (fits Fiat Dino):

Ignition on but not running: terminal 67 (alternator field) 10.0v, terminal
15 (battery) 10.8v  (Note that I think the battery is OK-- this reading is
separated from it by wires, switches, and whatever that lead to a voltage
drop)
Running at 1700 rpm with lights off: 12.3 and 13.1
Running at 1700 rpm with lights on: 11.5 and 12.3

With old regulator reinstalled:
10.3 and 11.2
12.3 and 13.1
11.0 and 12.0

Today at 3000rpm with lights off with the old regulator 11.8 and 12.8-

*Two weeks ago I had 13.5 and 14.3v at these terminals with the same voltage
regulator at 2000 rpm.*

Is my alternator dying?
On a normal car one could just pull it off and have it tested, but its not
so easy on a Dino. (Read as MAJOR PITA)

Thanks,

Jim