Problems with ignition system

[65kingfish]

I have a 65 Plymouth Cuba with electronic ignition. The car has new wiring harness from year one but the problem is after running the car for a little while the coil is getting so hot it's making the car hard to start and the coil is breaking down at high RPM's but you can take the ballast resistor off and connect the two wires from the ballast resistor and it will run fine and the coil want get near as hot as it was and the car starts a lot better. What could be my problem any help would be much appreciated. Thanks.....

 

[RedFish]

Don't know. Condition reads exactly opposite of how it should be. The coil should get a full 12 volts in start and the ballast resistor is lowering the voltage in run to prevent coil overheating.

 

[dano]

What coil are you using?

 

[67Dart273]

Could be wrong coil

Could be a BAD coil

Could be no, or miswired, or wiring problem with ballast resistor wiring

Again as above, "what coil" How is the system wired and ARE you using a / the proper ballast resistor

First thing would be to measure coil + voltage with engine running and post that here

And measure battery voltage with engine running, warm, at good fast idle and post that

 

[65kingfish]

Don't know. Condition reads exactly opposite of how it should be. The coil should get a full 12 volts in start and the ballast resistor is lowering the voltage in run to prevent coil overheating.

Your exactly right. I also thought it should be opposite from what it's doing.

 

[65kingfish]

What coil are you using?

I have ran a stock coil and the last coil I ran and it did the same thing it was a accell 8140. Both coils have done the same thing but now I have installed a new accell 8140 coil and by passed the ballast resistor and everything is working like its suppose to. I really don't understand why it's happening like it is but any help would be great.

 

[player1up]

Hmm, The accell 8140 says it needs 9v for optimal spark output so running it with the ballast bypassed may cook it. Are you by chance running it horizontally or vertically? I know some coils don't like being on their sides, causes them to overheat. A quick google search came up with some people having the same issue, crapping out soon after install. I ran a stock mopar small epoxy 12v coil on my slant for 5 yrs without any issues ( ballast bypassed of course ) seemed to start and idle better...

 

[67Dart273]

Check battery charging voltage with engine running, both with bypass in circuit and bypassed.