this is the ignition module that I replaced on my 84" F150 (302, automatic, FWD). the wiring in general is in rough shape and has been hacked pretty bad. I used this wiring harness (Painless Performance Products 30812, Painless Ford Car Chassis Harnesses | Painless Performance Products ) as the replacement. wired it in according to their drawing. I got the truck to run but once it got warmed up it cut off and will not crank. the coil got extremely hot. i'm including some more pictures showing what I've got. the #2 wire that i'm using to provide power is the same one that was used before. it has 12V with the key in the run position. the #1 wire only has 5V with the key on and i'm not using it. also, i'm not running the ballast resistor as it wasn't used before .I hope this isn't confusing and any help will be most appreciated.

 

First off the Ignition Coil is an 8 volt coil so if you try to run it on 12 volt battery voltage it will burn up. That is what the Ballast resister is for to drop the voltage while the engine is running.

When the engine is cranking the battery voltage is bypassed by the starter solenoid on the fender. This give a higher voltage for starting the engine.

The diagram shows the Ignition switch doing all the switching as in later 80s model Fords but it looks like yours uses the starter solenoid for that.


Here is a drawing I made of my 1977 F250. Note the it used a resistance wire vs the Ballast resistor.

/

 

thanks very much for the info