[C2] Ballast Resistor
Team Owner
Joined: Jul 2006
Posts: 22,182
Likes: 4,178
From: Kannapolis NC
Thread Starter
Instructor
Joined: Apr 2018
Posts: 179
Likes: 56
From: Trenton Michigan
2021 C2 of the Year Finalist - Unmodified
Hmmmm. I'm confused. The 1963 shop manual says that the Ignition Resistor should be 1.4 -1.6 ohms. The one in my car measures ~2.4 ohms. Does the quoted parts and accessory entry supersede the repair manual?? Where can I get a "Black Dot" resistor that is NCRS approved?
Regards,
Jerry
Regards,
Jerry
Melting Slicks
Joined: Jul 2004
Posts: 2,867
Likes: 195
From: Maryland
The .30 ohm resistor was matched to the 091 coil. Later in the 63 model year there was a service bulletin to address customer complaints regarding. premature points pitting. The solution was a 1.8 ballast resistor.. The 087 coil was the match to the resistor which was used later in the 63 model year. My 62 has a replacement 1.8 ballast resistor with a 091 coil and it works just fine.
Le Mans Master
Joined: Feb 2012
Posts: 5,371
Likes: 2,878
From: Western Massachusetts
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2019 C2 of Year Finalist (stock)
2015 C2 of the Year Finalist
The .30 ohm resistor was matched to the 091 coil. Later in the 63 model year there was a service bulletin to address customer complaints regarding. premature points pitting. The solution was a 1.8 ballast resistor.. The 087 coil was the match to the resistor which was used later in the 63 model year. My 62 has a replacement 1.8 ballast resistor with a 091 coil and it works just fine.
Dan
Racer
Joined: May 2017
Posts: 371
Likes: 39
From: richmond, va.
I'm not one hundred percent sure which is correct 0.3 or .03 but that's what the GM parts book showed so that's what I typed. I do know the 195174 resistor shows (blue stripe) ( 1.8ohms) so I believe 0.3 probably is correct .
Team Owner
Joined: Jul 2006
Posts: 22,182
Likes: 4,178
From: Kannapolis NC
It would be hard to ever detect any "performance" difference with a 1.8 ohm resistor in a high performance engine, but you might notice the points burning faster with the .3 ohm in any setup. I'd run a 1.8 ohm in either one personally.
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
Melting Slicks
Joined: Sep 2005
Posts: 2,710
Likes: 901
From: Warminster PA
When making low resistance measurements with a DVM (or any ohm meter for that matter), you need to take into account the resistance of the meter leads. Short the leads together and make note of the reading. Could be zero, could be more, lets say 0.5 ohms. If your ballast measures 2.3 ohms, you need to subtract the meter lead resistance from that measurement so in the example above, 2.3 - 0.5 = 1.8 ohms. Some meters have a function that allows you to zero out the lead resistance while holding the leads together. Non of this takes into account the measurement tolerance of the meter either, but for the purpose of this measurement it shouldn't really matter.
Tom
Tom