QuestionI have a 1986 Ford F 150 300 6 cyl Standard
Truck was sitting idling and died.
Checked. No spark at the plugs
replaced coil, distributor, TFI Module.
The engine will turn over and there is power to the coil while it is turning over, but none in the RUN position. Accessories wipers, fan motor and guages activate and work.
Are we looking at the run position on the ignition switch being bad, or are we looking for a wire...could it be something else...does it need exorcised and/or recycled
AnswerHi Jim,
For years back then, they used a ballast resistor in the wire to the coil in the run position. This allowed the coil to get battery voltage while cranking, but then run on about 9 volts. I believe it was to prolong the life of the coil.
The resistor is about 3 to 4 inches long, and about 3/4 of an inch wide. Usually bolted to the firewall, or the drivers side fender.
Usually, if the resistor was the problem, it wasn't burned out, but rather, the wire connections were loose or corroded.
Run a jumper wire from battery positive post, to the batt post on the coil, and see if it will run then. (they used to call that "hot wiring it")
Van
Van
