On Tue, 2 Apr 1996, David E. Brown wrote:
> when I did see some spark at the plug. At this point, with a new
> coil and ballast resistor, I have no spark even from the coil lead
> to ground, but the coil primary (switch side) has power. I don't
> get it.
Part of this should be easy to trouble shoot. You have a new coil, and
power to the coil primary. If the coil is good and has power, then you
have to have a fault in the circuit through the points. This circuit
makes a circuit through the coil primary to ground when the points close
and disconnects the circuit when the points open. The changing voltage
in the primary induces a higher voltage in the secondary. If no current
flows through the primary, or if it always flows through the primary,
there will be no spark.
Disconnect the lead from the coil to the points. Take a jumper wire,
attach it to the points side of the coil primary. With the ignition on,
and power to the other side of the primary, momentarily ground the other
end of the jumper wire to the chassis. Have an assistant hold the coil
center wire an eighth inch from ground and look for a spark. If no spark,
your new coil is faulty.
If you do get a spark that way, I would bet either your points are not
opening, your condensor is shot, or there's a permanent short to ground,
or a permanently open circuit (for example, oxidized points) in the circuit
that goes through the distributor, the points, and to ground.
It should be fairly easy to check all these possibilities.
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
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