smoking ballast resistor

[bstan70rr]

i was cranking on the starter for a good bit (about a minute), and the ballast resistor started smoking. got the car started, but i am worried about that smoke.

the only thing i did was disconnect the alternator to dress up the engine. it is all back together, and everything seems to be ok????????????????????

i am not even sure of the function of the ballast resistor if anyone wants to give me a lesson.

any ideas?

 

[Big John]

In a stock '69 ignition with a single ballast resistor, the ballast resistor drops the voltage to the coil after the engine starts. You turn the key to start it bypasses the resistor and there's a full 12 volts going to the ignition coil making for a "hotter" spark and easier starting. When you release the key to "run", the ballast resistor drops the voltage to the coil.

If you have a Mopar electronic conversion with a dual resistor, it works the same except when the key is in "start" the voltage is dropped through one side of the ballast resistor and when the key is in "run" the voltage is dropped farther through the other side of the ballast resistor. Same principal, higher voltage to start and lower voltage to run.

Back to your problem. If the ballast resistor was smoking while starting, I would assume you have a dual resistor. It could mean the resistor is getting ready to fail or it could mean you got some water behind it. It could also mean nothing. The resistor does create some of its own heat and cranking for a minute will get that side of the resistor hotter then it usually gets.

I always say that if you own a Mopar, you need to carry a spare ballast resistor in the glove box. This would be a good time to make sure there's one in there.

 

[6R9Runner]

You might want to take a look at an electrical schematic for this to make the most sense: The ballast resistor reduces voltage from the voltage regulator to the coil when the engine is running (i.e. NOT cranking). When cranking the engine, the ballast resistor is bypassed (BROWN wire from ignition). Since the ballast is not new (you made no mention of replacing it), the smoking sounds unusual, but the prolonged cranking is a clue. Did you leave the key on for a long time? Then the ballast might overheat if you were cranking for a long time, and did not turn the key fully to OFF (where you can remove the key) each time. Continual smoke indicates high current flow which is bad for the coil or other components. Did you clean the ballast resistor?

 

[bstan70rr]

I did clean it. Tried not to do anything to the "coil/spring?" side. Painted the bracket?

Everything is back to normal. It starts right up.......no smoke.

Anyway, going to put a spare in the glovebox.

Thanks.