I have been having some trouble with my wiring lately, it's an 85 w 150 the problem is sometimes the motor will die like someone shut it off, it has happened while in gear driving and while sitting idleing

I'm sure it's gotta be in the ignition wiring somewhere I just cant figure out where. here's an example truck will start run and then shut off boom like someone shut the key off, radio is still playing. then the truck will just crank over forever and nothing happens go back a while later and sometimes it will start. I'm sure it's to do with power cuz I've put a timing light on it while cranking it and it's not firing. the spark box thing on the firewall is new and has been tested (both at the store and on another vehicle and tests fine) the coil is under a year old and has been tested and is good. the distributer is under a year old and seems to test fine, my bro says if the thing on the ceramic thing on the firewall was goofy it wouldn't do this. there is something on the fender by the battery that I havn't changed, could it do this? has something like this happened to anyone else? at this point me and my bro are seriously debating weather or not we have to rewire the whole truck

thanks in advance for any help

 

I guess a little more details might be helpful, truck has a 360, a wiend dual plane intake, street demon carb and headers

 

It's called a ballast resistor and i would check it first. They heat up and melt the terminals.

 

would it cause the truck to shut off it it was already running?