Hello Everyone, I replaced the Ballast Resistor in our 73 Dart, the car started I let it run while cleaning up and it quit, wont restart. I have not had a chance to dig into it yet but, kinda wondering what you all thought? Its a 1973 Dart Swinger 318.
Replaced ballast resistor started ran and died
- Thread starter F1swinger
- Start date
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moparlvr166
Well-Known Member
Good looking car. Need more info, no start? does it not crank, cranks ok no fire, cranks and tries to start but can't.
moparlvr166
Well-Known Member
Were you having any problems before ballast replacement? Do you have any test equipment?
67Dart273
Well-Known Member
Why did you replace it? Resistors are simple. The 2 pin you simply check for continuity, and wave/ tap/ whack it to check for intermittent. The 4 pin is exactly the same, except "the long way" you have 2 resistors in one box
For a short time you can simply jumper around the resistor to see if it's a problem.
CLIP your voltmeter on the coil + terminal and ground. Turn key to "run." You should NOT have full battery voltage, but instead should have around 6-10V
Now watch the meter and using the key, crank the engine. Now, while cranking, you should have full battery voltage and at least 10.5V or more.
Check for spark. "Rig" (or buy) a test spark gap, or make one from a plug. "rig" a wire, SOLID core, not resistor wire, and you can use low voltage wire if you keep it away from metal. Watching the gap, crank the engine using the KEY. You should have nice hot blue snappy sparks at least 3/8" long and typically longer.
If not, turn the key to "run" and separate the distributor 2 wire pickup connector. Take the engine harness end (not the distributor) and tap the bare end against ground, such as the distributor housing or other unpainted surface. Each tap should give you once single "snap" spark.
Module MUST be grounded. Undo it, clean/ scrap around the bolt holes and if possible get some start lock washers and remount. "Work" the connectors in/ out several times to scrub the terminals and "feel" for tightness. The distributor connector, especially is vulnerable because there is almost no current there.
For a short time you can simply jumper around the resistor to see if it's a problem.
CLIP your voltmeter on the coil + terminal and ground. Turn key to "run." You should NOT have full battery voltage, but instead should have around 6-10V
Now watch the meter and using the key, crank the engine. Now, while cranking, you should have full battery voltage and at least 10.5V or more.
Check for spark. "Rig" (or buy) a test spark gap, or make one from a plug. "rig" a wire, SOLID core, not resistor wire, and you can use low voltage wire if you keep it away from metal. Watching the gap, crank the engine using the KEY. You should have nice hot blue snappy sparks at least 3/8" long and typically longer.
If not, turn the key to "run" and separate the distributor 2 wire pickup connector. Take the engine harness end (not the distributor) and tap the bare end against ground, such as the distributor housing or other unpainted surface. Each tap should give you once single "snap" spark.
Module MUST be grounded. Undo it, clean/ scrap around the bolt holes and if possible get some start lock washers and remount. "Work" the connectors in/ out several times to scrub the terminals and "feel" for tightness. The distributor connector, especially is vulnerable because there is almost no current there.
67Dart273
Well-Known Member
Maybe it DIDNT, maybe it's another problem. WHY did you replace it?
Also, on Mopars, if you leave the key in "run" and engine stopped while doing other things, the coil draws current. This is hard on coils, resistors, and modules. GM HEI is DIFFERENT. Those modules normally do NOT draw coil current with the engine stopped
I replaced it because of the Run while starting problem and I do know that if you leave the key "on" the coil draws but I don't think I left it on long enough to burn it out. Besides it was running when it quit and that's what drew my mind to the Module because I saw it so many times in GM's I guess.
Run whke starting is either...
If it cranks and significantly less voltage at the coil than battery voltage then the ignition switch or wiring is suspect
If in run you have about 8 volts at the coil that's normal
If in run you have less than 8 volts at the coil that's not normal
If in run you have about 0 volts at the coil that's normal
67dart273 will fill in the details
- The ignition switch
- The wiring from the ignition switch
- The bulkhead connectors
- The wiring at the ballast.
If it cranks and significantly less voltage at the coil than battery voltage then the ignition switch or wiring is suspect
If in run you have about 8 volts at the coil that's normal
If in run you have less than 8 volts at the coil that's not normal
If in run you have about 0 volts at the coil that's normal
67dart273 will fill in the details
67Dart273
Well-Known Member
Did you do any testing as I outlined? You cannot just stand there and look at it and "wish" it fixed.
There are several things can be wrong besides the module
DO THE TESTS I outlined. If it is not getting power to the coil, jumper power to the coil + temporarily and try it.
RE-read my earlier post, and keep this in mind.
Those of us trying to provide help, are NOT getting paid. This is a two way street. If you are going to use up our free time, the least you can do is make good use of it
There are several things can be wrong besides the module
DO THE TESTS I outlined. If it is not getting power to the coil, jumper power to the coil + temporarily and try it.
RE-read my earlier post, and keep this in mind.
Those of us trying to provide help, are NOT getting paid. This is a two way street. If you are going to use up our free time, the least you can do is make good use of it
Well I understand you cant wish it fixed and right now I cant do any tests I like most of you have a job. I understand your not getting paid, I was just looking for thoughts on any ones behalf. I'm very sorry if I bothered you or am taking anyone away from any thing.
Dave999
Well-Known Member
or indeed the wrong ballast resistor combined with the correct coil can burn out the igntion module...
basically using a standard coil and module the resistor should be one of 1.2- 1.4 ohm, If you use one of the 0.25, 0.5 or 0.8 ohm ones designed for the orange or chrome box. it's a recpie for reducing the life of all parts.
basically the wrong resistor rateing can be enough to tip something that was on its way out...over the edge.
the reverse... using a points ballast or a standard electronic ballast with an orange box just converts the orange box performance back closer to standard.. obviously coil primary resistance plays a part....... its a system.... coil and ballast are matched pair.
a mis match causes unforeseen outcomes either somthing gets too hot or performance is less than it should be for the money invested.
an igntion designed or a 10 second blast at 6000 rpm isn't good for 4 hours on the freeway then the 1/2 hour traffic jam getting back into town.
so the combination of igntion box coil and ballast should be matched to your application.
Dave
basically using a standard coil and module the resistor should be one of 1.2- 1.4 ohm, If you use one of the 0.25, 0.5 or 0.8 ohm ones designed for the orange or chrome box. it's a recpie for reducing the life of all parts.
basically the wrong resistor rateing can be enough to tip something that was on its way out...over the edge.
the reverse... using a points ballast or a standard electronic ballast with an orange box just converts the orange box performance back closer to standard.. obviously coil primary resistance plays a part....... its a system.... coil and ballast are matched pair.
a mis match causes unforeseen outcomes either somthing gets too hot or performance is less than it should be for the money invested.
an igntion designed or a 10 second blast at 6000 rpm isn't good for 4 hours on the freeway then the 1/2 hour traffic jam getting back into town.
so the combination of igntion box coil and ballast should be matched to your application.
Dave
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Dave999
Well-Known Member
oops my bad 0.5 or 0.6 with points but the factory manuals quote this at 70-75 F and NIL AMPS flowing which makes no sense to me
well 3-4 amps flow and it get way hotter than 75F so its resistance increases
coil sees 8 to 9 volts in operation, that means ballast sees 3-4 with approx 14 volts across the system due to the alternator being ON.
so the coil provides 2/3rd of the resistance and the ballast 1/3
its a low primary resistance coil
say 1 ohm
that tallys with a ballast of say 0.5
1.5 ohm resistance in this situation would mean 9.5 amps flowing .... Bye Bye points
3 ohm total gives 4.6 amps flowing add in impeadence due to switching the coil off and on and you would be closer to the 3-4 amps specified as ok for the points
my only issue is i can't find the primary resistanace of the 8 volt coil
anyway comes down to how you specify the resistance of the ballast
but yes I agree i was wrong above on my 1.5 ohm suggestion
Dave
well 3-4 amps flow and it get way hotter than 75F so its resistance increases
coil sees 8 to 9 volts in operation, that means ballast sees 3-4 with approx 14 volts across the system due to the alternator being ON.
so the coil provides 2/3rd of the resistance and the ballast 1/3
its a low primary resistance coil
say 1 ohm
that tallys with a ballast of say 0.5
1.5 ohm resistance in this situation would mean 9.5 amps flowing .... Bye Bye points
3 ohm total gives 4.6 amps flowing add in impeadence due to switching the coil off and on and you would be closer to the 3-4 amps specified as ok for the points
my only issue is i can't find the primary resistanace of the 8 volt coil
anyway comes down to how you specify the resistance of the ballast
but yes I agree i was wrong above on my 1.5 ohm suggestion
Dave
The resistance of the Chrys ign coil as stated in the 73-78 Motors Manual is 1.6-1.79 ohm pri/9.4-11.7k sec res for Prestolite coils. Essex coils were 1.41-1.55/8-10.2 k. All at 75*f.
Current draw was 3.0 amp engine stopped, 1.9 amp engine idling.
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current draw was
Current draw was 3.0 amp engine stopped, 1.9 amp engine idling.
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current draw was
It ended up being what I thought it was, the Control Mod. I thought there is no way a 16,000 mile car that all the wiring is original and never hacked into is gonna have a wiring problem!
MOPAROFFICIAL
Oogliboogli
It happens. I've had voltage Regulators go bad in a matter of a day or two and no wiring problems. Glad you figured it out, ignition control module.
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