Howdy. I'm finally getting some time to get the old hunting rig back up and running after a 5 year break. It's a 1983 302 F150 with a big top-drive rack (mad max style Texas brush rig with boat throttle and push pull cables to operate shifter & brakes from the roof rack, steering column up top with linkage down into the cab). I'm already done with all the typical stuff like draining gas and replacing carb. The fuel pump was bad so I installed an electric pump. Mice had eaten a lot of the wiring so I decided to run new wiring up to the rack (I never drive it from inside the cab anyway). I ran an 8 gauge wire direct from the battery up to a fuse block on the rack and ran a bunch of switches off the fuse block: Light bar, push button starter, fuel pump switch, and a switch to turn on the ignition. Everything is working.. the push button cranks over the starter and the fuel pump is pumping fuel. My problem is that I have the 12 volts running direct from my switch to the ignition coil (I have 12v at the + post on the coil), but I'm not getting any spark. This truck had already had the ignition altered before I got it (it has the older style distributor from the 70s which accepts plug wires with male ends vs the 80s style where the plugs have female ends and the distributor has male posts) so I don't know if it had an ignition control module/duraspark or whatever at any point but I'm not seeing anything resembling one now.

So my question is: did I wire the coil up the right way? 12v direct to the + post on the coil should provide spark (assuming the coil is still good) right? And then ground from the - post on the coil run over to the - on the battery? Or am I missing something that needs to be between the 12v+ switch and the coil?

And help is much appreciated.

Thanks.

Mike

 

Here is a drawing to hopefully make clear the way I wired it up. As it is right now, there is no spark when cranking with the ignition switch turned to on, but there is 12V at the + post on the ignition coil with the ignition switch turned to on.

 

You messed up. I am going to assume you have a points distributor? You should run the 12v+ to the + of the coil like you have it (it does need a resistor in this line, but we can get into this later) But the negative of the coil does not run to the ground or battery negative. The negative of the coil runs to the distributor. The points inside the distributor ground and unground the coil, that is what makes the spark. If you do not take the ground on and off the coil, no spark. That is all the ignition box does if you have one. It grounds and ungrounds the coil. Same thing is happening but instead of the mechanical points switching the ground, the electronic module is doing the switching.

 

Ah! That would make sense. Can you tell from this picture if it's a points style distributor? All of my experience before this is with 80s and newer trucks with the ignition control module. I assume there's just a ground post on the lower section of the distributor? (sorry for the crappy pic, the truck is at the ranch and this is all I have on hand at the moment. I HAVE replaced those plug wires haha)


I am aware of the need for a resistor on the 12V+ to coil, just haven't gotten to it yet as I was hoping to get spark and get it cranking over before I bought any more parts.

 

Hard to tell what it is. All you have to do is pull the distributor cap off. If you have a little paddle wheel under the rotor, it is electronic. Or you will have points and a condenser under there. If it's electronic, you need to power the ignition box and the coil. If it's electronic, it will have 3 wires going from the distributor to the ignition box. One of those wires is the ground for the system and is bolted to the body of the distributor inside.