So I have a 1986 w150. It had a 318 that died so I dropped a 360 in it, out of a 1987 1ton. Before the 318 died, the spark control unit also died. so I opted for a standard electronic ignition set up. I replaced the distributor, installed the ECU added the ballast resister and an external resister coil and all was just fine. motor later suffered catastrophic failure, in went the 360. put a few thousand miles on her and all was mostly fine. a little hard starting from time to time but that was a fuel issue. here recently the truck wouldn't start after just a five minute trip to the dump on two different occasions. the 360 had a ratty heavily molested thermoquad 800cfm on it that easily flooded so I didn't want to deal with it and just bought a holley 600cfm and after it was installed and I was doing a little tuning I had put my hand on the coil and dam near burnt myself from the heat coming off it and after that the truck just wouldn't start. no spark! coil fried! Went down and got another one, same external ballast style. and I have the same issue. the coil heats up faster than the motor! I went through the twenty different steps listed for checking the ignition system in my auto store version chilton repair manual.
So heres the rundown on my test results.
-Key on running and not running, have batt voltage at +side of coil
-At -side of coil when running 7 to 8 vlots, with 4pin connector disconnected key on, not running, have batt voltage.
-tested ground on ecu, good 0.4ohms
-ballast resistor 1.5ohms post to post book doesn't state ohms range????????
-single pick up distributor ohms 275.at 4pin connector, spec states 150-900 is good range
-did spark test by jumping the ground post to a ground with coil wire near grounded portion of motor. no spark with 4pin connector attached and again disconnected, book says replace coil or ecu depending on connection or not of the 4pin, but I did it with the new coil and truck runs good but coil over heats like the old one. and the only test for the ecu was the ground at the pin-5
-had continuity on all wiring and batt voltage at the other pins instructed to test. I'm not all that convinced the ecu is bad considering the truck runs, but I'm at a loss as to what else would cause the coil to get so dam hot, and Id really like to not burn this new coil up too. All connections are clean and tight,
WTF am I over looking?

 

Need info/pics of the ignition you put in it. My guess is that you have constant positive and negative going to the coil. You need to check the wiring and make sure it's all correct.

 

You were spot on Moparite!!! I don't know what the hell possessed me to make such a rookie mistake, but it turned out that I attached positive power to both sides of the ballast resister. Duhhhh! One snip of a wire and my problem was solved!!! Thank you for pointing out the obvious. That dam resister had been hiding in plain sight for days! I wish it was a snake. I would have gotten fixed faster! Thanks again!!!