Thescotts06

Just purchased a 66 Dodge Coronet 500, had a few thing that I planned on doing. Have only start and drove a few times. With the start yesterday, but wouldn’t start. Has 383 4 speed with around 1900 miles on it. I am getting fuel to carburetor. I have 12 volts to positive side of coil with key on. I have checked to see if getting spark from coil; got that. There is no ballast resistor, not sure what to try next?

Archer

The -

Are you getting spark at the plug?
Easiest way to find out is with an inductive pick-up.

Archer

Thescotts06

Haven’t try that yet, will tomorrow. Thanks

Thescotts06

Just checked, no spark at plug. Thinking Ignition control box may be bad. Notice that ballast resistor sometime before had been hooked up, wondering where it’s just out(bypassed) if that could of damaged the ignition control box

Thescotts06

Just talked with previous owner said has electronic ignition, that it didn’t need it ( ballast resistor)?

Archer

The -

If it's the std Mopar ECU (black, orange or chrome control box), yeah it needs the dual ballast resistor.
If it's after market, it might or might not.

Archer

Thescotts06

It’s the molar P4120505 , orange color, but there is not the standard old style points. It’s a small black module.

Archer

The -

If it looks any thing like this one:
https://www.yearone.com/Product/chrysler-b-body/fdp505#

It will have and electronic (pointless) distributor and will need a ballast resistor.

Not knowing what was done to the car, the first thing you have to do is confirm spark to the plugs.

And yes, those ECUs can go bad, especially some of the newer ones.
Although failure is not frequent, I always keep a spare ECU, ballast resistor and voltage regulator around.

Archer

Thescotts06

Yes looks like that one, I checked ballast resistor have 1.5-1.8 ohms across terminals. Is that about right. I believe I could wire it back in. It appears they just though a piece of wire with male ends to connect the wires together. Thanks I’ll put new ECU on tomorrow and hook ballast resistor back in.

Archer

The -

Make sure the ballast resistor is good (and remember what I said about a spare).
We used to call them "burn boxes" for a reason.
1.6 ohms is about right for a single resistor.

Archer

Thescotts06

Ok, thanks I appreciate it. I let you know if I get running

Thescotts06

No luck, ECU didn’t help. Been told that my points module in distributor got burnt up due to no ballast resistor. Told me to install a MSC 8386 distributor. This would take care of voltage spikes and more reliable, not sure what to do, what you thoughts?

Archer

The -

OK, there aren't any "points" in an electronic distributor.
I would just pick up a Mopar or after market copy (like from JEGS) electronic ignition conversion kit (ECU, Dizzy, harness, resistor), and replace the whole thing.
S/b about $150 and about an hour's work.

Better than doing a mismatch and trying to piece things together, if you're not sure about what's going on.

Archer

Thescotts06

Ok, thanks.

RacerHog

Maybe test the Reluctor in the distributer...

Thescotts06

Thanks, that maybe my problem.