Burning up Points and Condensor
Thread Starter
Instructor
Joined: Nov 2006
Posts: 209
Likes: 38
From: Gettysburg
Burning up Points and Condensor
Need help troubleshooting ignition issues. Recently had Wilcox rebuild the distributor. I added a new radio suppression resistor to the stock position on the wire loom per original. Also found and added a "rebuilt" correct dated 515 Voltage regulator.
Since these changes, I have gone through three sets of points (each set lasted about 20 miles). I checked the coil (stock 202) and had 1.7 on primary and 11.3 on secondary. Checked ohms at ballast resistor and got no readings. (So how was the car running??)
I do not know if the issue is coincidental to recent additions or related to them. Any ideas are welcome.
Also, anyone know what the correct number for the ballast resistor was (D1110??) Application is early 1966 327.
Thanks//Mike
Since these changes, I have gone through three sets of points (each set lasted about 20 miles). I checked the coil (stock 202) and had 1.7 on primary and 11.3 on secondary. Checked ohms at ballast resistor and got no readings. (So how was the car running??)
I do not know if the issue is coincidental to recent additions or related to them. Any ideas are welcome.
Also, anyone know what the correct number for the ballast resistor was (D1110??) Application is early 1966 327.
Thanks//Mike
Team Owner
Joined: Jul 2006
Posts: 22,192
Likes: 4,180
From: Kannapolis NC
Never heard of a radio suppression resistor. Perhaps you meant noise suppression condensor or capacitor (for radio noise on AM).
If the ballast resistor is open, the car won't run when you release the key UNLESS it has been bypassed in some way. The wire to the coil should be on one end, and the wire to the ignition on the other. Depending on the application, it should read in the 1-2 ohm area with an ohmeter. IF it has been bypassed, that could explain burning up your points. With points used, it should always be in the line between the ignition and the coil pink wire.
If the ballast resistor is open, the car won't run when you release the key UNLESS it has been bypassed in some way. The wire to the coil should be on one end, and the wire to the ignition on the other. Depending on the application, it should read in the 1-2 ohm area with an ohmeter. IF it has been bypassed, that could explain burning up your points. With points used, it should always be in the line between the ignition and the coil pink wire.
7th Gear
Joined: Jul 2017
Posts: 7
Likes: 0
Need help troubleshooting ignition issues. Recently had Wilcox rebuild the distributor. I added a new radio suppression resistor to the stock position on the wire loom per original. Also found and added a "rebuilt" correct dated 515 Voltage regulator.
Since these changes, I have gone through three sets of points (each set lasted about 20 miles). I checked the coil (stock 202) and had 1.7 on primary and 11.3 on secondary. Checked ohms at ballast resistor and got no readings. (So how was the car running??)
I do not know if the issue is coincidental to recent additions or related to them. Any ideas are welcome.
Also, anyone know what the correct number for the ballast resistor was (D1110??) Application is early 1966 327.
Thanks//Mike
Since these changes, I have gone through three sets of points (each set lasted about 20 miles). I checked the coil (stock 202) and had 1.7 on primary and 11.3 on secondary. Checked ohms at ballast resistor and got no readings. (So how was the car running??)
I do not know if the issue is coincidental to recent additions or related to them. Any ideas are welcome.
Also, anyone know what the correct number for the ballast resistor was (D1110??) Application is early 1966 327.
Thanks//Mike
Race Director
Joined: Apr 2015
Posts: 17,571
Likes: 3,460
From: Fresno California
Connect a voltmeter to ground and to the + side of the ignition coil. Check the voltage at the coil with the ignition switch in the "on" position. You should read between 6 and 9 volts. Anything higher and you will burn out your points. If the reading is high replace your ballast resistor, it's a very inexpensive fix. D1110 is the correct resistor for your car.
Le Mans Master
Joined: Jan 2000
Posts: 5,074
Likes: 1,558
From: Poway CA
2025 C1 of the Year - Unmodified Finalist
2024 C1 of the Year Finalist - Unmodified
2023 C1 of the Year Finalist - Unmodified
2022 C1 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (stock)
2019 C1 of Year Finalist (stock)
2016 C1 of Year Finalist
Team Owner
Joined: Jul 2006
Posts: 22,192
Likes: 4,180
From: Kannapolis NC
Connect a voltmeter to ground and to the + side of the ignition coil. Check the voltage at the coil with the ignition switch in the "on" position. You should read between 6 and 9 volts. Anything higher and you will burn out your points. If the reading is high replace your ballast resistor, it's a very inexpensive fix. D1110 is the correct resistor for your car.
Since the car runs, the ballast resistor is either good or bypassed. My guess is you're getting over 12v to the coil in both start and run due to incorrect wiring.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
This has to be a mistake as we all know points never fail...
Seriously, if you have "no reading" across the ballast resistor its clearly wrong whether you mean infinity or a dead short.
As 65GGvert suggested retrace your wiring...
I don't know what you added into the wiring with a radio suppression resistor (no such thing), so remove it until you solve the running problem
Seriously, if you have "no reading" across the ballast resistor its clearly wrong whether you mean infinity or a dead short.
As 65GGvert suggested retrace your wiring...
I don't know what you added into the wiring with a radio suppression resistor (no such thing), so remove it until you solve the running problem
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Jan 2003
Posts: 17,693
Likes: 3,683
From: Central Arkansas
Sounds like your ballast resister has been bypassed by some creative re-wiring. There's not a heck of a lot to trouble shoot on a ballast resister - either it has continuity and works or it doesn't have continuity and doesn't work (and the motor should die when the key is released). I'm sure there have been a few rare exceptions or malfunctioning resisters but not many. I would trace the circuits out in both directions from the resister per the factory wiring diagram.
Le Mans Master
Joined: Apr 2000
Posts: 5,104
Likes: 1,362
From: New York New York
2024 C1 of the Year Finalist - Unmodified
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2023 C1 of the Year Finalist - Unmodified
When you say the points burn out are the contacts pitted and is the end of the point arm blue?
With the key on and the points closed you should read approx. 3.6 amps and without a ballast it could read 7.0 amps.
Amperage is what does the damage to the points and coil not voltage.
Post a picture of the ballast wiring.
Obviously you have too much amperage across the points causing the failure.
One other possibility is the by pass circuit from the starter is staying energized by passing the resistor.
Where did you connect the "radio suppression resistor"? Can you post a picture?
Joe
With the key on and the points closed you should read approx. 3.6 amps and without a ballast it could read 7.0 amps.
Amperage is what does the damage to the points and coil not voltage.
Post a picture of the ballast wiring.
Obviously you have too much amperage across the points causing the failure.
One other possibility is the by pass circuit from the starter is staying energized by passing the resistor.
Where did you connect the "radio suppression resistor"? Can you post a picture?
Joe
Racer
Joined: Nov 2012
Posts: 463
Likes: 63
From: Tampa Florida
A ballast resistor can only fail open, in which case the engine will not run with ignition on. If it is the proper resistor, look elsewhere. Something else is causing higher than normal voltage at the points. Also agree a bypassed resistor would not kill new points in 20 miles. If that were true, daily cranking of the starter would burn them out first.
Thread Starter
Instructor
Joined: Nov 2006
Posts: 209
Likes: 38
From: Gettysburg
Thanks for the responses guys. To answer a couple of your comments.
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Last edited by Old Pervette; Jul 26, 2017 at 06:30 PM.
Team Owner
Joined: Jul 2006
Posts: 22,192
Likes: 4,180
From: Kannapolis NC
Thanks for the responses guys. To answer a couple of your comments.
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Drifting
Joined: Nov 2007
Posts: 1,711
Likes: 179
From: Hightstown NJ
Thanks for the responses guys. To answer a couple of your comments.
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Had the car since 1983, NO mods to the original wiring harnesses. No bypass wire
Radio resistor (per NCRS) that mounts to coil bracket was one of the recent additions I mentioned (goes to + coil?)
Checking resistance on the ballast pinned the meter at 70 ohms on both hi/lo scale
Car starts up and runs fine but around 10-15 miles starts missing and breaking up. Came home on a deadstick from the hillside road one time. Put in new points and condensor and she ran fine....for a while. Repeat cycle.
Per JAVAC3, I will test + coil and ground with key on for voltage. Will advise
Verne
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
If you added your location to your profile there might be somebody that could come by and help you out.
Prob time you posted a picture of your points sitting in the distributor and their condition...
Prob time you posted a picture of your points sitting in the distributor and their condition...
Last edited by Frankie the Fink; Jul 27, 2017 at 07:46 AM.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
That's why I suggested the guy post his locale,
I have a stock coil and a NAPA coil and a physical inspection by another set of eyes or swapping in a spare part would prob solve the issue in 10 minutes. There are only a few things that can 'take out' points in 20 miles and most have to do with the high tension side of the ignition.
The OP has yet to answer Plaidside's question about the condition of the failed points which is important.
Done here.
I have a stock coil and a NAPA coil and a physical inspection by another set of eyes or swapping in a spare part would prob solve the issue in 10 minutes. There are only a few things that can 'take out' points in 20 miles and most have to do with the high tension side of the ignition.
The OP has yet to answer Plaidside's question about the condition of the failed points which is important.
Done here.