1974 Bronco 320 no spark

[elijha]

Hello all
I have a 1974 with the 320 engine in It.I have not worked much on this model truck more in to the VW and Older Fiats . It did catch fire, Plug from the distribution to the start melted which in turn burned through some fuel line. I do have everything changed up new spark plug wires the 8mm once, new start coil, performance as well. I am not getting any spark on the plug. Is there a relay switch or a fuse box that I need to look in too. Engine does turn strong I did look under the distributor Capt turns just fine but no spark in there as well. What is the best was to start troubleshooting this and does anyone have a diagram of that model electrical.
I’ll appreciate all the input please

 

[Tiha]

Turn the Key on.

With a test light, the ignition coil should have +12v on the + side of the coil. If not that is most likely your problem.

If you have 12 V there. Then check the - side of the coil. It should go directly to the distributor. It should flash while you are cranking the engine.

If it does not flash most likely you need to adjust the points.

 

[elijha]

Hi and thank you for the response. So I checked the distributor I have is the mechanical one with magnetic pick up.
I changed the starter coil new batteries new distributor cap and router,wires start solenoid as well as clean all the ground. Any idea what else it could be. I am thinking about changing the wire harness for the ignition what do you think.

 

[Motech]

The test @Tiha gave you still stands. Check for key-on power at coil. Fires burn wires.

 

[Motech]

Then, if no power there, you'll have to track it down. Meanwhile, you could use a jumper wire from battery positive to coil positive and see if you get spark. If so, shut her down and go find that missing power supply.

No fuses, comes straight from ignition switch. But if that's a Pertronix ignitor in your distributor, your power source may route through a ballast resistor depending on the coil impedence.