1970 Mustang Coil Voltage ?

I have a 1970 Mach 1 351W that until today was running like a top.
It died at a stop light and I couldn't get it started. I had to have it
towed home.

I since put on a new coil, an old voltage regulator ( that was working when
I replaced it ) an old starter solenoid ( that was working when I replaced
it ) and still no start. The engine is turning over, I am getting plenty of
fuel, but no spark at the plugs or out of the coil.

I checked the coil voltage going into the coil and it is only reading 3.75
volts.

I was wondering if this voltage should be 12 volts ?

And if it should be 12 volts, does anyone know why I might be getting the
low voltage going into the coil ?

Also I have an electronic ignition module in the distributor.


Thanks in advance,
Jim

www.jimseiders.com

"Jim" > wrote in message
t...
>
> I have a 1970 Mach 1 351W that until today was running like a top.
> It died at a stop light and I couldn't get it started. I had to have it
> towed home.
>
> I since put on a new coil, an old voltage regulator ( that was working
> when
> I replaced it ) an old starter solenoid ( that was working when I replaced
> it ) and still no start. The engine is turning over, I am getting plenty
> of
> fuel, but no spark at the plugs or out of the coil.
>
> I checked the coil voltage going into the coil and it is only reading 3.75
> volts.
>
> I was wondering if this voltage should be 12 volts ?
>
> And if it should be 12 volts, does anyone know why I might be getting the
> low voltage going into the coil ?
>
> Also I have an electronic ignition module in the distributor.
>
>
> Thanks in advance,
> Jim
>
> www.jimseiders.com
>
>
Have you replaced the ignition module? If I remember correctly they don't
last forever.

"Les Benn" > wrote in message
...
>
> "Jim" > wrote in message
> t...
>>
>> I have a 1970 Mach 1 351W that until today was running like a top.
>> It died at a stop light and I couldn't get it started. I had to have it
>> towed home.
>>
>> I since put on a new coil, an old voltage regulator ( that was working
>> when
>> I replaced it ) an old starter solenoid ( that was working when I
>> replaced
>> it ) and still no start. The engine is turning over, I am getting plenty
>> of
>> fuel, but no spark at the plugs or out of the coil.
>>
>> I checked the coil voltage going into the coil and it is only reading
>> 3.75
>> volts.
>>
>> I was wondering if this voltage should be 12 volts ?
>>
>> And if it should be 12 volts, does anyone know why I might be getting the
>> low voltage going into the coil ?
>>
>> Also I have an electronic ignition module in the distributor.
>>
>>
>> Thanks in advance,
>> Jim
>>
>> www.jimseiders.com
>>
>>
> Have you replaced the ignition module? If I remember correctly they don't
> last forever.
>
What ignition module. 70 mustang used points and condenser.
check the back of the ignition switch make sure you have 12 or more volts
there.
if so check large pink wire in black fiberglass wrap it should also have 12
volts at far end away from ignition switch.

if you are talking about an after market ignition module like petronix or
mallory you need to Check the coil, it should be a 4 ohm type not the newer
8 ohm higher voltage type.
mismatched impedance will mess up the unit and the voltage readings

walt peifer wrote:
> "Les Benn" > wrote in message
> ...
>> "Jim" > wrote in message
>> t...
>>> I have a 1970 Mach 1 351W that until today was running like a top.
>>> It died at a stop light and I couldn't get it started. I had to have it
>>> towed home.
>>>
>>> I since put on a new coil, an old voltage regulator ( that was working
>>> when
>>> I replaced it ) an old starter solenoid ( that was working when I
>>> replaced
>>> it ) and still no start. The engine is turning over, I am getting plenty
>>> of
>>> fuel, but no spark at the plugs or out of the coil.
>>>
>>> I checked the coil voltage going into the coil and it is only reading
>>> 3.75
>>> volts.
>>>
>>> I was wondering if this voltage should be 12 volts ?
>>>
>>> And if it should be 12 volts, does anyone know why I might be getting the
>>> low voltage going into the coil ?
>>>
>>> Also I have an electronic ignition module in the distributor.
>>>
>>>
>>> Thanks in advance,
>>> Jim
>>>
>>> www.jimseiders.com
>>>
>>>
>> Have you replaced the ignition module? If I remember correctly they don't
>> last forever.
>>
> What ignition module.



"Also I have an electronic ignition module in the distributor."

Rob





70 mustang used points and condenser.
> check the back of the ignition switch make sure you have 12 or more volts
> there.
> if so check large pink wire in black fiberglass wrap it should also have 12
> volts at far end away from ignition switch.
>
> if you are talking about an after market ignition module like petronix or
> mallory you need to Check the coil, it should be a 4 ohm type not the newer
> 8 ohm higher voltage type.
> mismatched impedance will mess up the unit and the voltage readings
>
>

"trainfan1" > wrote in message
et...
> walt peifer wrote:
>> "Les Benn" > wrote in message
>> ...
>>> "Jim" > wrote in message
>>> t...
>>>> I have a 1970 Mach 1 351W that until today was running like a top.
>>>> It died at a stop light and I couldn't get it started. I had to have it
>>>> towed home.
>>>>
>>>> I since put on a new coil, an old voltage regulator ( that was working
>>>> when
>>>> I replaced it ) an old starter solenoid ( that was working when I
>>>> replaced
>>>> it ) and still no start. The engine is turning over, I am getting
>>>> plenty of
>>>> fuel, but no spark at the plugs or out of the coil.
>>>>
>>>> I checked the coil voltage going into the coil and it is only reading
>>>> 3.75
>>>> volts.
>>>>
>>>> I was wondering if this voltage should be 12 volts ?
>>>>
>>>> And if it should be 12 volts, does anyone know why I might be getting
>>>> the
>>>> low voltage going into the coil ?
>>>>
>>>> Also I have an electronic ignition module in the distributor.
>>>>
>>>>
>>>> Thanks in advance,
>>>> Jim
>>>>
>>>> www.jimseiders.com
>>>>
>>>>
>>> Have you replaced the ignition module? If I remember correctly they
>>> don't last forever.
>>>
>> What ignition module.
>
>
>
> "Also I have an electronic ignition module in the distributor."
>
> Rob
>
>
>
>
>
> 70 mustang used points and condenser.
>> check the back of the ignition switch make sure you have 12 or more volts
>> there.
>> if so check large pink wire in black fiberglass wrap it should also have
>> 12 volts at far end away from ignition switch.
>>
>> if you are talking about an after market ignition module like petronix or
>> mallory you need to Check the coil, it should be a 4 ohm type not the
>> newer 8 ohm higher voltage type.
>> mismatched impedance will mess up the unit and the voltage readings
3.75 volts at the coil is not unusual as there is a series limiting resistor
in the ignition switched hot lead that limits current to the coil and
subsequent voltage as with the engine stopped and the points closed the coil
would overheat/burn out because of it's relatively low resistance. I vote to
check/change the electronic ignition module.
KenG

Thanks for all of the great replies, I changed out the electronic module in
the distributor with a Pertronix Ignitor.
Also new rotor and cap.
Still not starting.

I noticed that it is doing something different though.
It still won't start, but when I let off of the ignition switch ( after
trying to start ), it sounds like it fires one time. Then nothing.

When I tried to check to see if I had anything coming from the coil, I held
the coil wire to the block, there was nothing, except a good shock to me
only when my wife released the ignition switch and the starter disengaged.

I will check the voltages at the switch today.



Thanks,
Jim
www.jimseiders.com







"Jim" > wrote in message
t...
>
> I have a 1970 Mach 1 351W that until today was running like a top.
> It died at a stop light and I couldn't get it started. I had to have it
> towed home.
>
> I since put on a new coil, an old voltage regulator ( that was working
> when
> I replaced it ) an old starter solenoid ( that was working when I replaced
> it ) and still no start. The engine is turning over, I am getting plenty
> of
> fuel, but no spark at the plugs or out of the coil.
>
> I checked the coil voltage going into the coil and it is only reading 3.75
> volts.
>
> I was wondering if this voltage should be 12 volts ?
>
> And if it should be 12 volts, does anyone know why I might be getting the
> low voltage going into the coil ?
>
> Also I have an electronic ignition module in the distributor.
>
>
> Thanks in advance,
> Jim
>
> www.jimseiders.com
>
>
>
>

"Jim" > wrote in message
et...
> Thanks for all of the great replies, I changed out the electronic module
> in
> the distributor with a Pertronix Ignitor.
> Also new rotor and cap.
> Still not starting.
>
> I noticed that it is doing something different though.
> It still won't start, but when I let off of the ignition switch ( after
> trying to start ), it sounds like it fires one time. Then nothing.
>
> When I tried to check to see if I had anything coming from the coil, I
> held
> the coil wire to the block, there was nothing, except a good shock to me
> only when my wife released the ignition switch and the starter disengaged.
>
> I will check the voltages at the switch today.
>
>
>
> Thanks,
> Jim
> www.jimseiders.com
>
>
>
>
>
>
>
> "Jim" > wrote in message
> t...
>>
>> I have a 1970 Mach 1 351W that until today was running like a top.
>> It died at a stop light and I couldn't get it started. I had to have it
>> towed home.
>>
>> I since put on a new coil, an old voltage regulator ( that was working
>> when
>> I replaced it ) an old starter solenoid ( that was working when I
>> replaced
>> it ) and still no start. The engine is turning over, I am getting plenty
>> of
>> fuel, but no spark at the plugs or out of the coil.
>>
>> I checked the coil voltage going into the coil and it is only reading
>> 3.75
>> volts.
>>
>> I was wondering if this voltage should be 12 volts ?
>>
>> And if it should be 12 volts, does anyone know why I might be getting the
>> low voltage going into the coil ?
>>
>> Also I have an electronic ignition module in the distributor.
>>
>>
>> Thanks in advance,
>> Jim
>>
>> www.jimseiders.com
>>
>>Sounds to me that you may have a shorted coil or the circuit from your
>>coil to your dist is shorted.Unhook the wire to the dist from the coil and
>>measure the voltage at the coil.It should read battery voltage.If it does
>>there is a short at the dist or the wire itself.,If not unground the coil
>>case and check the voltage. If it goes back up to battery voltage the coil
>>is shorted to ground!
KenG
>>
>>
>
>