[DeTomaso] Factory Shunt? was Re: Ammeter, was Re: Key difficult to turn

[MikeLDrew at aol.com]

In a message dated 10/15/12 17 43 23, guido_detomaso at prodigy.net writes:


> There was a factory shunt?  Guess I missed a few episodes here...my car 
> is a '73
> though.
> 
>>>Check out this photo:

http://www.poca.com/index.php/gallery/?g2_itemId=38308

The interesting part (the shunt) is unfortunately a bit out of focus.   
This is a NOS ammeter that I lifted out of a Ford box.   It's my understanding 
that this external shunt was standard.   I think the ammeter in my '72 also 
has this shunt installed.   Note that it's electrically hot all the time and 
completely lacking any insulation.   DOH!
> 
> >The shunt I took off I made long ago, before the internet.  The needle 
> stopped
> moving over time, something I wanted to address.  But a shunted gauge with 
> a
> non-moving needle beats walking home.
> 
>>>Indeed.
> 
> >And so am starting to question the wisdom of this whole project.  
> 
>>>As am I.   I suspect your original shunt was too shunty; that is, too 
much power was going past the gauge instead of through it.   You can see the 
original one is just a thin piece of brass.


> >Has anyone
> used the existing red wire off the ignition switch, that powers 
> everything(?)
> that goes on and off with the key, to only trip a relay, switching power 
> from a
> new third wire off the ammeter?
> 
> >>>I *think* that this is the scheme that Rick Moseley's relay kit uses, 
although he ties into the fusebox, not the ignition switch.   But I think what 
he does is have you unplug the red wire (that goes from the ignition switch 
to the fusebox) and plug it into one of his wires, which then goes to a 
relay, and the output from the relay then goes to the fusebox where the 
original red wire hooked up.   I *think*.

> >Taking just the fan current out of the ignition switch doesn't take all 
> the
> current away, as I'm finding out.
> 
>>>True dat.   But it certainly removes the largest consumers...

Mike