Ignition Coil keeps blowing out.

Ok, so update... My "Jack Of All Trades" buddy came by and showed me what was what. I actually feel a bit embarrassed now seeing how simple it all is.

First, "I" relay from solenoid did not go to positive on coil, it went to negative. So , theres that.

A lot of wires were wrapped up together with crusty electrical tape. We undid all of that and discovered a lot of bad and exposed wires.

Also the starter terminal looks horrible and is barely hanging on to the cable. Going to rewire and replace a few things tomorrow.

No ballast resistor. Not sure where that even came from or why the guy at O'Riley sold me one for this vehicle but it was only 7 bucks so I'm not sweating it too bad.

White wire got tossed.

Will update tomorrow. Thank you all again for your help AND PATIENCE! Although this is my 5th classic in the last 12 years, I'm still a total newb with this kinda stuff. I've lucked out with well running vehicles and never had to do much besides the basic tune up, alternator, starter swaps etc... Electrical is a foregeign language. This truck is definitely making me pay my dues but Im learning a bit and loving it!

The RESISTOR wire is spliced in series. There is a RED/GREEN wire coming from the RUN side of the ignition switch. This wire then CONNECTS to a PINK WIRE which is the resistor wire. This PINK RESISTOR WIRE then connects back to a RED/GREEN wire that connects to the starter relay on the BATTERY SIDE of the starter relay. From that connector there will be a BROWN wire that goes to the POSITIVE side of the ignition coil.  
  The starter relay internally sends the full 12 volts through the brown wire to the coil at the same time it engages the starter and when you release the start the original resistor wire is still engaged in from the run position. 
vic

Update*** Put wires and new wires in propper place. No sparks from solenoid but truck wouldn't start. Starter post was kinda loose, when tightened it improved response but still no dice. Motor trying to turn but gives up. Wondering if I have the wrong coil ( see photo on previous page) because it says " Use primary resistance wire or external resistor" on coil but Vic mentioned no ballast resistor so what external resistor would they be referring to
? Maybe starter is going? Just relieved to not immediately burn out solenoid when turning key. I have not been able to test any voltage due to no reader.

ok, soooo latest update. Checked starter, it's fine. put it back in, same issue as yesterday. charged battery. issue resolved. no sparks coming out of solenoid either. Truck fires up but won't stay running unless I hold key all the way to right. as soon as i let it it shuts off.

also, Vic says "no ballast resistor, PERIOD."  Don asks in the very first response to this post "Do you have the ballast resistor in the line that goes to the positive side of the coil that cuts the 12 volts from the ignition switch down to 6 volts?".

Im confused as to if there is a ballast resistor or not.

Again, truck now fires up but won't stay running unless I hold key all the way to right. as soon as I let go, it shuts off.

Simple test, turn the the key to run, engine off, do you have 6-12v at the coil + terminal? How many wires are connected tot he coil + terminal? If you ran a new wire from the I @ the solenoid, there should be 2 wires @ the coil +. Sounds like either you don't have the ballasted, or "run", wire hooked to the coil, or the ignition switch is defective.

one red wire hooked to the + on coil and it runs to the "I" on the solenoid. One black wire on the - of the coil and it runs to the distributor.

I did some hunting and found these two random taped together a few inches down the line but not connected to anything.


coil as is right now... red wire is the + going to "I" on solenoid, black is - going to distributor


solenoid as is right now ( everything here is good )


I spoke with Vic ( who's is totally awesome) earlier and he confirmed that most likely I either fried the resistor wire or its disconnected or damaged. He didn't mention anything about a 2nd wire going to the + of the coil though. Gonna hunt down a voltage reader tomorrow and run some tests

It could be connected to the I terminal or the coil + terminal. It's the run wire, and yes, you need to find it. It should have around 6v when the key is in the on/run position. I am suspicious of that Orange wire connected to ground there next to the solenoid. Is there a tracer on that wire? If so what color is the tracer stripe? I suspect, that is the run wire and should be connected to the I terminal. But having been connected to ground, the ballast resistor part of it upstream, towards the ignition switch, is probably toast.

That very well could be it. No tracer on it though. Its taped to the same bundle of wires that are connected to the solenoid ( excluding the "I" to coil + wire ).

Well, there are only so many wires that go into the engine compartment from the dash to that side of the engine. I pulled my run wire out and ran a new one when I switched to electronic ignition so I can't help with what color it was. There is a start wire, run wire, oil sending unit wire, temp sending unit wire, hot wire, and maybe a ground wire, .... other wires from the dash are the horn relay lead, brake light switch lead, gen light,  but they don't get that far. Are your sending units hooked up and working?

Good luck

as in the cooling system sending unit? i have no idea.

,,,,,,,like I said,,,,,,,,,until you run the tests I listed,,,,,all you are going to end up with is 100 confusing,,,,,,,,guesses,,,,,,,,you need to do 1 wire at a time.........

GOT IT!!!!! WOOOOHOOOOO!!!! So, as some of you suspected, that suspicious yellowish orange ground next to the solenoid was my resistor wire! I followed it to the bundle it was taped too, removed the tape and low and behold it was connected to the red/green resistor wire which actually fit perfectly in length to the coil once I removed yellow wire and put new terminal on on. Truck fired right up first try!! Thank you all for your time and valuable input, Vic for getting on the phone with me and Jimmy for the wire diagram.

look at this shit connection job from previous owner. I'm rattled this thing fired up and ran as many times as it did with resistor being grounded.

I'm glad you got it working. How the PO got it that screwed up is beyond me. I'd still check the voltage to that wire, it could likely be damaged and putting out less than 6v, even if the truck is now working. I'm surprised it didn't destroy the resistor part of the wire all together.

I bet those other 2 wires are the sending unit wires for the temp guage and the oil light. The sending units are on the drivers side of the engine, the temp is near the back of the head and the oil sender is below that on the side of the block. See if they are there and if there are any wires connected to them. On the 67 wiring diagram I have it shows the temp wire being red with a white tracer and the oil being white with a red tracer. But they may be different on your truck. If there is nothing connected to them, they are easy to test. When you ground the oil wire the light should come on. Grounding the temp wire should move the needle.

On 61 the yellow is voltage constant and red green runs from coil to ignition with it resisted to a pink behind the panel. That goes for falcons to 65' also, not that it matters.