360 Turns-over but will not fire

[fred1226]

Hey Folks,
I've been having ignition problems with my 84 W 150 4x4. It has a 360 with a 4bbl. carb. The problem is it would fire when you let-off the key but as of the other day all it does is turn-over. I've replaced the distributer (dual-pickup), the eletcronic control unit and the ignition coil. I've tested the voltages at the battery 13.50Vdc and the distributor and found 6.75Vdc but I have no spark coming out of the coil going to the distributor when I pull the coil wire off at the distributor and hold it near the engine block and crank the engine. I've installed all new plug and coil wires. I've tested the ingition resistor but I'm going to replace it because I don't know what amount of resistence it should have. What do I do next. PLEASE HELP. I'm pulling out my hair, what little bit I have.

[Dodgevanman]

Looks like the ballast resistor has finally gone bad. You said that it would fire when you let off the key (off of START position)...that's usually a good sign that the resistor has gone bad. Also keep in mind that the ignition switch could be the culprit as well.

[fred1226]

Thank You, Dodgevanman for the information.

[evanrude]

having the same trouble with my 87 ram checked the computers on freinds 86 ram no luck truck will crank but no fire at dist wire
replaced everything even tried other harness have igniton switch on order now
any suggestions?

[swami2806]

FIRST swap out the ballast. They are cheap and gremlins are at them constantly. They are easy to install but don't forget to disconnect battery. THEN check harmonic balancer. If the key is sheared or partiall sheared, or the rubber dampener in it is bad, it will cause the engine to miss. Loosen all your accessory belts and see if there is any play in it. A shot balancer would not affect spark from the coil though. Check all the fusable links in that case. Follow the battery hot wire until you see wires with purple (I think) bulges on them. If any look melted replace.