Resistor wire on 79 F150

is...

It's a wire of the correct resistance right in the harness. Can't remember the color, maybe pink, but it's marked...

It's connected to the ignition switch but may pass through a connector or two on the way...

IIRC, the 'resistor' wire is like the fuse-links, a 'spliced-in' wire with different insulation AND a different feel and flexibility... and can be found by following positive side wire back from coil terminal.

As it must dissipate heat, it shouldnt be wrapped into the harness.

Dont rule out a faulty ignition switch, as that occurs much more often.

Also try forum on

ford-trucks.com

I recall there being a resistor wire on the older vehicles with breaker point ignition.... it was buried in the harness along the fire wall. IIRC, it was identifiable by its fabric jacket. I don't recall such a wire on DuraSpark 2 systems... if memory serves correct, the module contains a current limiter for the coil - I've been mistaken before and this may be no exception....

The fender mounted modules were the biggest concern with these systems. They would die but could be brought back to life by pouring cold water on the module.

FWIW... open wires in a 12 volt system are rarely "self healing". Corroded connections usualy get to the point where their current handling capabilities wont allow the load to power up.

Rather than "think" you have a particular concern, you could use a test light (in this case the test light is the most appropriate tool) to verify power to the coil. A little testing takes away most of the guesswork and allows us to perform a timely and, hopefully, economical repair.

is...

By the way, the resistance is 1.1 ohms for that vehicle....

suddenly

again.

Think it's red/light green...

connector