Complete loss of spark.

[ferret76]

Decelerating to a stop at a roundabout the engine suddenly lost power and then stopped. Unable to restart. So far I have changed the condenser and rotor arm, I have changed the coil and changed it back with nil result. From what I can see I am getting no spark out of either coil which makes me think there is nothing getting to the coil. What to check from here? Any suggestions welcome.

[mogbob]

First clean up your battery terminals and ensure the main cables are securely clamped. With a multi meter check what voltage you have across the main terminals, record the reading. With the ignition "on "( only for a short time ) do you get
the same voltage at the feed to the coil ? Switch off the ignition.
Is the earth lead in the distributor sound ? The wire is small and not very robust so subject after many years to giving up the challenge.
Bob

[ferret76]

12.30 across battery, 11.30 at coil. Earth in distributor is sound.

[ferret76]

Also can someone clarify which terminal of the coil connects to the distributor. Car is pos earth.

[myoldjalopy]

If the car is +ive earth, then the +ive connection on the coil goes to the distributor, where the current goes to earth when the points close.

[mogbob]

Observation. The battery voltage is a little low 12.6/7 volts would be healthier. Not the cause but a battery overnight charge
might improve things.
The voltage drop of 1 volt is indicative of poor connections ..battery to solenoid ,ignition switch , fuse box,
coil. After 60 odd years a clean up ( back to bare metal ) might improve matters. The fuses might warrant
a more critical look. So often it has been said on the forum that fuses "look OK " and it later turns out they are
suspect / faulty.
Take them out of the fuse box to test and clean the holding clips of any rust / corrosion. Ensure the metal
ends of glass fuses are firm.
Other things to look at. The low tension wire from the coil to the distributor. Is that sound / clean both contact ends ?
Do the resistance check with the multi meter on Ohms and wiggle / flex the wire whilst doing it. The circuit is breaking down somewhere along the line. No circuit = no spark.
Bob

[ferret76]

Problem solved. In my haste to fit the new condensor on the side of the road with two crying children in the car and traffic wizzing past my backside, I connected the wire on top of the plastic insulator instead of underneath it where it needed to be in contact with the LT wire.
Schoolboy error.
Cheers Bob for your help.

[mogbob]

Glad you cracked it ! Good man for " 'fessing up " to the schoolboy error. I've made more than a few of those in my life.
Look after that little family of yours and safe motoring.
Bob

[bmcecosse]

Thank goodness it wasn't the coil.......