[DeTomaso] Alternator found

[David D Fisher]

Now I'm curious enough that I'll have to go out and measure the gauge of the new and  stock cables.  The one shipped with this Alt (which is rated at 140A but has a test tag showing 160A) looks to be a smaller diameter (might just be the silicon shielding is thinner) as the stock Pantera cable and it is about 4 ft long.   Anyone care to guess how long the run is from the alternator through the ammeter and to the battery?
 
Given Bill's explanation of the ammeter,  it looks like it can handle the current if the connections are good.
 
 Side note,  I was messing with the dash and only hand tightened the ammeter for a quick drive.  Within 20 minutes the connection was plastic melting hot (all consumers on w/ 80A alt trying to keep up), but once I wrench tightened, they didnt overheat again.
 
David
 
 
 
 

________________________________
 From: Brian <bd8134 at gmail.com>
To: SOBill at aol.com 
Cc: fisher95020 at yahoo.com; julian_kift at hotmail.com; guson at home.se; detomaso at realbig.com 
Sent: Wednesday, September 12, 2012 6:39 PM
Subject: Re: [DeTomaso] Alternator found
  

The stock battery cable to the amp meter is 8 maybe 6 gauge and not designed for more than maybe 80 amps.
The cable gauge required depends on the length, expected load and possibly if it is in free air to cool.
There are many sites out there to calculate the size, here is one.
http://www.gtsparkplugs.com/WireSizeCalc.html

Worse situation is a battery low on charge from cranking after a troublesome warm start, ac, cooling fans, electric fuel pump, headlights, etc on.
The full amperage required to charge the battery and power all the electrics will feed through the cable running from the alternator to the fuse panel / main feed.
This high reading you won't see on the amp meter, it will only show the battery charge amperage, this is when you might be cooking the wiring.
I think most vendors supply a new cable with their alternators.
A 4 or 2 gauge cable is a wise choice depending on the alternator.

On Sep 12, 2012, at 8:31 PM, SOBill at aol.com wrote:

> FWIW,
> 
> The story of the internals of the Pantera ammeter (with pictures)  are at 
> _http://www.panteraplace.com/page178.htm_ 
> (http://www.panteraplace.com/page178.htm) .   Inside the Pantera ammeter, between the two ammeter terminals is 
> a heavy, solid  metal bar through which the current into or out of the 
> battery creates  a magnetic field. The indicator needle mounts a very small 
> magnet which  responds to the magnetic field in the metal bar to indicate 
> charging/discharging  current. 
> 
> Pantera ammeters which get hot have loose and/or corroded internal  or 
> external connections.
> 
> A properly working alternator only provides enough  current to maintain the 
> nominal battery voltage.
> 
> The alternator current that goes into the electrical loads of the  car, 
> other that the portion which is charging the battery, does not go through  the 
> ammeter. As configured in an OEM Pantera, all the electrical loads, except  
> the battery, are on the alternator side of the ammeter.
> 
> As configured in an OEM Pantera electrical system, the ammeter only  
> indicates current going into or out of the battery.
> 
> Have fun  today,
> 
> _sobill at aol.com_ (mailto:sobill at aol.com) 
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso