[DeTomaso] what should I have done while the car's in the shop?

Tue Sep 24 16:36:22 EDT 2013

I agree with the battery voltage dropping fast with just lights is generally
a bad battery.  Lights that instantly go out, and voltage dropping to near 0
when lights are turned on(no engine running), is almost always a bad battery
cable connection.  Give away is the voltage going back to 12v after turning
the load off.  A battery doing this will not likely take a boost either.

Something that most do not realize is that the ignition systems (pre-hei)
are a 9v system.  Chrysler vehicles all had ballast resistors on them (every
dodge will have a spare in the glove box), other manufacturers used a
special type of wire to drop voltage.  The reasoning behind this was due to
battery not being able to provide 12v when cranking the engine over.  Oh the
simple days.. 

Doug

From: Sean Korb [mailto:spkorb at gmail.com] 
Sent: Tuesday, September 24, 2013 2:04 PM
To: Doug Scott
Cc: Pantdino; detomaso at poca.com
Subject: Re: [DeTomaso] what should I have done while the car's in the shop?

That's what I remembered but I couldn't find any internet coroboration... 

that seemed weird so I thought maybe it would dip down to 3V while cranking
but it really didn't seem right.  If it's below 9V the coil won't be able to
generate spark.  And usually with a bad battery the voltage drops really
fast even with the headlights.  

A battery short is the worst to diagnose since it's usualy a sulfated path.
Sometimes it's a resistor, sometimes it's a short and sometimes it's open.
Maddening.

sean

On Tue, Sep 24, 2013 at 11:54 AM, Doug Scott <doug at pickbbs.com
<mailto:doug at pickbbs.com> > wrote:

Back in the day before all this new-fangled testing hardware they use now,
we would take a meter that did voltage and amperage measurements(AVR meter).
We would check battery voltage, then have someone crank the engine over
(ignition disabled) and record the voltage that the battery dropped to
immediately when the engine first cranked, and also record voltage while the
engine was cranking over.  The meter has a variable load tool with it, and
you would connect the larger leads up to the battery in addition to voltage
leads.  Crank the knob on the meter until the volt meter is reading what it
read while the engine was cranking.  Once you see that reading, record the
amperage reading you have now.  Battery voltage should not go below 9v while
cranking.
Normal starter draw for an 8 cylinder engine is approx. 200-275 amps.

A high starter draw does not necessarily mean bad starter.  I would think
that if you are seeing 3.5v when cranking you have a bad battery.  As for it
being almost new, remember, there is a reason they have a warranty,
sometimes they fail.

If it is the starter, I would suggest getting one of those new gear
reduction starters.

Doug

-----Original Message-----
From: detomaso-bounces at poca.com <mailto:detomaso-bounces at poca.com>
[mailto:detomaso-bounces at poca.com <mailto:detomaso-bounces at poca.com> ] On
Behalf
Of Pantdino

Sent: Monday, September 23, 2013 9:32 PM
To: spkorb at gmail.com <mailto:spkorb at gmail.com> ; detomaso at poca.com
<mailto:detomaso at poca.com> 
Subject: Re: [DeTomaso] what should I have done while the car's in the shop?

voltage across posts with car disconnected = 12.55v

w headlights on = 12.00v

So battery is OK?

-----Original Message-----
From: Sean Korb <spkorb at gmail.com <mailto:spkorb at gmail.com> >
To: detomaso <detomaso at poca.com <mailto:detomaso at poca.com> >
Sent: Mon, Sep 23, 2013 5:25 pm
Subject: Re: [DeTomaso] what should I have done while the car's in the shop?

Check the battery for voltage (at the posts) with your headlamps on.  It
should never get below 9V.  The battery could be bad but it's under warranty
so not a problem.

It could also be the cables.  This instruction sheet to check cable and
connection voltage drop is very thorough.
http://www.aa1car.com/library/voltage_drop_testing.htm
It's a long way to go from the battery to the starter.

I can't remember... did you try engaging the starter manually with jumper
cables?

On Mon, Sep 23, 2013 at 7:56 PM, Pantdino <pantdino at aol.com
<mailto:pantdino at aol.com> > wrote:

>
> This is also a follow-up on the "starter system problem" thread.  I
> had my son turn the key and the relay/ solenoid on the firewall was
> definitely the source of the buzzing-- I could feel it as well as hear
> it. But I replaced that item and the buzzing is unchanged.  Also, when
> the starter is engaged the battery voltage drops to 3.5v or something,
> from which I concluded the starter has a short to ground and the
> relay/solenoid is freaking out from all the current going thru it.
> (What a great 60's term.) :-)
>
>
> I planned to have some maintenance / update work which I can't / don't
> want to do done before the Fun Rally next year anyway, so I guess I
> may as well just have the car flat-bedded to a shop
>
> Last time I spoke with Steve Wilkinson about replacing the timing
> chain / gear set he recommended replacing the water pump while we were
> there since there would no extra labor for that.
>
> So at this point I think the car needs
>
> 1) starter motor
> 2) timing chain / gear set
> 3) water pump
> 4) check harmonic balancer for condition, replace if necessary.
>
> Anything else I should have done while it's there?
>
>
> Jim
>
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--
Sean Korb spkorb at spkorb.org <mailto:spkorb at spkorb.org>
http://www.spkorb.org <http://www.spkorb.org/> 
'65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera #1382
"The more you drive, the less intelligent you get" --Miller "Computers are
useless.  They can only give you answers." -P. Picasso
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Sean Korb spkorb at spkorb.org <mailto:spkorb at spkorb.org>
http://www.spkorb.org
'65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera #1382
"The more you drive, the less intelligent you get" --Miller
"Computers are useless.  They can only give you answers." -P. Picasso