breakerless point coversion
Thread Starter
Instructor
Joined: Sep 2015
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From: Waretown NJ
breakerless point coversion
I have been having a problem with points burning after only a few hundred miles on my 1970 350, 350. I would like to convert my original to pointless. Does anyone have a suggestion as to brand and model that they are happy with? Thanks, Rob
Team Owner
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From: Kannapolis NC
Just to save some possible time and money, I'd check to make sure the ballast resistor is in the circuit. The points shouldn't burn even in a few thousand miles, mine don't. You should have around 7-8 volts on the wire from the ballast to the coil when it's running. 12v or over will cause some points burning.
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Actually the car would have a yellow black speckled resistance wire running to the coil and as it heats up it generates more resistance dropping the voltage and preserving the points. If this wire was burned or replaced with standard wire that would explain the issue. If you do not have this resistance wire inline you could possibly buy some or install a ballast resistor used on 1963-1967 cars. https://willcoxcorvette.com/corvette...resistor-63-67. To do this you would need to run your coil wire in one side of the resistor and then run a wire from the coil to the other side.
If you do decide to go with a breaker-less ignition system and you do have the yellow wire mentioned above... Don't use it to power up the breaker-less system because they require constant 12 volts.
Willcox
If you do decide to go with a breaker-less ignition system and you do have the yellow wire mentioned above... Don't use it to power up the breaker-less system because they require constant 12 volts.
Willcox
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Thread Starter
Instructor
Joined: Sep 2015
Posts: 132
Likes: 8
From: Waretown NJ
thanks for all the replies. I removed the ballast resistor several years ago and installed a coil with the resistor built in. As for the yellow wire I will check that out. I will look into the conversions mentioned.Thanks again, Rob
Team Owner
Joined: Jul 2006
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From: Kannapolis NC
Something with that setup is what's burning your points. Too much spark.
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
What's the resistance of the coil? Also, do you have a functioning condenser across the points?
Former Vendor
Joined: Aug 2006
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Willcox
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From: Crossville TN
The ignition system will burn points when the power circuit to the coil is drawing too much current. This can occur when the resistance wire has been replaced with regular wire...or when a 'high energy' coil is inserted into the system...or if you play your radio when the engine is OFF but ignition is still in the ON position.
Key in ACCY (accessory) position (one click CCW when key is inserted) should be used when playing radio, etc. with engine off. That position will not have current flowing through the ignition circuit.
If you have points, your ballast resistance (resistance wire OR resistor) must be correct and the coil must match that setup. Also, spark gap should be set per stock requirements. If you inserted a 'high energy' coil in a stock points system and opened the plug gap accordingly, you will burn up points due to excessive current flow.
Key in ACCY (accessory) position (one click CCW when key is inserted) should be used when playing radio, etc. with engine off. That position will not have current flowing through the ignition circuit.
If you have points, your ballast resistance (resistance wire OR resistor) must be correct and the coil must match that setup. Also, spark gap should be set per stock requirements. If you inserted a 'high energy' coil in a stock points system and opened the plug gap accordingly, you will burn up points due to excessive current flow.
Last edited by 7T1vette; Jul 28, 2016 at 11:50 PM.
Thread Starter
Instructor
Joined: Sep 2015
Posts: 132
Likes: 8
From: Waretown NJ
The ignition system will burn points when the power circuit to the coil is drawing too much current. This can occur when the resistance wire has been replaced with regular wire...or when a 'high energy' coil is inserted into the system...or if you play your radio when the engine is OFF but ignition is still in the ON position.
Key in ACCY (accessory) position (one click CCW when key is inserted) should be used when playing radio, etc. with engine off. That position will not have current flowing through the ignition circuit.
If you have points, your ballast resistance (resistance wire OR resistor) must be correct and the coil must match that setup. Also, spark gap should be set per stock requirements. If you inserted a 'high energy' coil in a stock points system and opened the plug gap accordingly, you will burn up points due to excessive current flow.
Key in ACCY (accessory) position (one click CCW when key is inserted) should be used when playing radio, etc. with engine off. That position will not have current flowing through the ignition circuit.
If you have points, your ballast resistance (resistance wire OR resistor) must be correct and the coil must match that setup. Also, spark gap should be set per stock requirements. If you inserted a 'high energy' coil in a stock points system and opened the plug gap accordingly, you will burn up points due to excessive current flow.
Thread Starter
Instructor
Joined: Sep 2015
Posts: 132
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From: Waretown NJ
Looked at the wiring and no yellow wire or ballast resistor. the coil is regulated. The voltage to the coil with the key on is 12 volts. When running the voltage is 12-13 volts, but the voltage on the other side of the coil shows 7-8 volts when running.If I put breaker less ignition in does it need constant 12 volts to the system, and since I only have 7-8 volts out of the coil will it still work? Thanks for all the help, Rob
Team Owner
Joined: Jan 2006
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From: Crossville TN
Some breakerless systems are designed to use the existing power wires in the car; in that case you DO use the resistance wire. Other brands require a full 12 volts for the electronic ignition module; in that case, you need to remove the resistance wire and feed the module from an appropriate 12 volt source.
In either case, the ignition system manufacturer will tell you what is needed (or you can read the instructions or search the internet).
In either case, the ignition system manufacturer will tell you what is needed (or you can read the instructions or search the internet).
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Odd 1970 cars didn't use a ballast resistor... so my money is on the fact that the yellow black speckled wire got toasted and replaced and the PO installed a resistor to drop the voltage. When you removed the ballast resistor you probably shot straight 12 volts to the coil and this is what is cooking your points.
Willcox
Willcox
There's two issues the OP has not answered yet. What is the resistance (ohms) of the coil (which has a great effect on how many amps he's switching with the points) if he is correct that he has no ballast resistance, and does he have a functioning condenser attached (to suppress points burning due to the flyback high voltage arcing) at the coil negative terminal line.
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Looked at the wiring and no yellow wire or ballast resistor. the coil is regulated. The voltage to the coil with the key on is 12 volts. When running the voltage is 12-13 volts, but the voltage on the other side of the coil shows 7-8 volts when running.If I put breaker less ignition in does it need constant 12 volts to the system, and since I only have 7-8 volts out of the coil will it still work? Thanks for all the help, Rob
Thread Starter
Instructor
Joined: Sep 2015
Posts: 132
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From: Waretown NJ
There is a condenser for the points which was installed new with the last tuneup, about 200 miles ago.. I measured the voltage on 1 side of the coil,the key on and not running, with the motor running and also disconnected the coil wire so the vehicle would not start taking a reading during cranking.The 7-8 volts was on the side of the coil feeding the points. How do I tell the resistance of the coil? It just says on the case no external resistor needed. Thanks, Rob
Tech Contributor
Joined: Jun 2004
Posts: 20,860
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
There is a condenser for the points which was installed new with the last tuneup, about 200 miles ago.. I measured the voltage on 1 side of the coil,the key on and not running, with the motor running and also disconnected the coil wire so the vehicle would not start taking a reading during cranking.The 7-8 volts was on the side of the coil feeding the points. How do I tell the resistance of the coil? It just says on the case no external resistor needed. Thanks, Rob
You'll need to buy or borrow a volt-ohmmeter to measure the coil primary resistance (from the plus + terminal to the negative - terminal). Or possibly just remove the coil and take it to a parts store, they probably have a meter there and would measure it for you. Either way, just make sure that the harness wires aren't connected to the coil when you make the measurement.
I'm curious what measurement number you get.