Ballast Resistor Identification Quiz

[Bill O.]

I've been looking for a "correct" ballast resistor for my '62 Vette and been through the CD and the archives to get educated...I'm not sure I've got it so please check me out.

The resister on the left column seems to be correct for '56 - '59 Corvettes since it has no dot, a tab on the band, the DR logo, the compression weld and a straight platform under the treminals.

The resister in the right column seems to be correct for late '59 through '62 Vettes because it has the above plus a "trench" or "notch" runnig across the entire length of the platform under the terminals. And even though the tab shoulders are not as "rounded" as the other example, I'm led to believe that this vairation is acceptable.

What say you?...and thanks as always.

Bill

[Jack H.]

Re: Ballast Resistor Identification Quiz

There's the physical appearance and then there's the resistance value. For late C1 Corvettes the 'hot' ignition setup was used (0.3 ohm ballast with, typically, an '091 coil). I'm used to seeing the early form of the ceramic (trough connects the two contact screws but does NOT extend all the way to the outside edges) on cars into the '58 range.

BUT, without data on the winding resistance of the ballast, I don't think you can tell the Corvette version of the part from the typical passenger car resistor...

[John D.]

Re: Ballast Resistor Identification Quiz

Bill, As Jack mentioned a typical 091 used the .3ohm resistor block/ballast resistor. D1111 is on the Delco Box.
Talk about a hot spark. Good for starting and firing but the points don't last very long. Try NAPA CS786P points.
By the way the "dot" is service replacement. I assume you mean the black dot.
My 63 NOS D1111 for my NOS 091 coil has a round spot weld that we call a dot.
I don't know if the 62 BR is the same configuration of porcelain.
If you determine the BR on the right side of your phototo be correct then use a dremel with a cutting blade on it to slice the back side of the bracket. Then get the bracket plating and then tack weld it together again. JD

[Loren L.]

Re: Ballast Resistor Identification Quiz

"Black dot is service replacement" is the BIGGEST LOAD OF MIS-INFORMATION ever posted on this or any other board.
Page 286 of Noland's Book 1 - picture lower left hand of the page is 60 #2269 (you will find this car in a number of poses - it seems that Chevrolet would reach out in the middle of a year and bring a car for photo purposes; in 1960, #2269 was that car; pictures of the interior, trunk, undercarraige, etc are here). My car is #2279 so I arranged with Noland for 16 X 20 copies; this shot has a nice black dot in the middle.
The black dot is for IDENTIFICATION ON THE LINE BECAUSE TWO BALLAST RESISTORS WERE USED and even the plant weenies thought that maybe
they should try to install the right part.

[Jack H.]

Re: Ballast Resistor Identification Quiz

If memory serves, the issue of whether or not the resistors were differentiated by ID marks (black dot vs. blue stripe) was resolved by John Hinckley pulling the part drawing and reading the ECR block.

If I remember correctly, the ID marks were added to the part drawing effective 4/11/61. That would render the factory original vs. service replacement interpretation as a time sensitive issue depending on the model year of car, heh?

[Bill O.]

Re: Ballast Resistor Identification Quiz

They say that confusion is a higher state of knowledge than ignorance, so I should be happy that I'm gaining ground.

Dale Pearman's article on "1955-'62 Ignition Ballast Resistors" (CD) references the Chevrolet Chassis Parts & Accessories Catalog, dated October 1, 1962 as indicating all 1955 through 1963 Corvettes used part number 1931385...0.03 Ohms. Then in a 1983 catalog he found reference to two resistors...the first design (0.03 Ohms) and the second design (1.8 Ohms) He concluded that this was GM's answer to complaints about burned points particularly in single point applications. It was undetermined at the time when the change-over occurred. (interesting that the picture provided of an original 1962 BR has NO tab...and no black dot). I'm not sure where that leaves us on that issue.

BUT, can anyone confirm that the correct 0.03 Ohm BR for a '62 did indeed have the "notch" or "trench" in the platform under the treminals?

Thanks to all for their input.

Bill

[John H.]

Re: Ballast Resistor Identification Quiz

Dale Pearman's article on "1955-'62 Ignition Ballast Resistors" (CD) references the Chevrolet Chassis Parts & Accessories Catalog, dated October 1, 1962 as indicating all 1955 through 1963 Corvettes used part number 1931385...0.03 Ohms. Then in a 1983 catalog he found reference to two resistors...the first design (0.03 Ohms) and the second design (1.8 Ohms) He concluded that this was GM's answer to complaints about burned points particularly in single point applications. It was undetermined at the time when the change-over occurred. Bill

Bill -

The "black dot" was added to the drawing of the #1931385 (0.3 ohm) resistor as Change #2 on 6-11-61. The production usage change and breakpoint was covered in TSB #Dr-577, issued 2/27/63 (below).

[Bill O.]

Re: Ballast Resistor Identification Quiz

John,

Should I put a 1.8 Ohm BR in an original 0.30 Ohm '62 caseing to perserve the points in a 340?

Thanks,

Bill

[John H.]

Re: Ballast Resistor Identification Quiz

John,

Should I put a 1.8 Ohm BR in an original 0.30 Ohm '62 caseing to perserve the points in a 340?

Thanks,

Bill

Bill -

I'm not sure you can do that - the wire resistance element is "potted" in some kind of ceramic material, and I don't know how you'd remove it to install in a different housing. The deduction is only one point.

[Bill O.]

Re: Ballast Resistor Identification Quiz

John,

Maybe this way per John DeGregory:

If you determine the BR on the right side of your phototo be correct then use a dremel with a cutting blade on it to slice the back side of the bracket. Then get the bracket plating and then tack weld it together again. JD

Thanks,

Bill

[Barry H.]

Re: Ballast Resistor Identification Quiz

Bill, John DeG was talking about how to remove the metal bracket to have it re-plated, then replacing it, (after plating) & tack welding it back together. Barry Holmes

[Bill O.]

Re: Ballast Resistor Identification Quiz

But could't you insert a different creamic...a 1.8?

[Jack H.]

Re: Ballast Resistor Identification Quiz

Thanks! My copy of the part drawing is VERY blurry with dates in the ECR block + companion text almost impossible to read. I now know the '4/11' date is actually '6/11'...

[Jack H.]

Re: Ballast Resistor Identification Quiz

Potted is the correct general term. My hunch is it could be a form of saurisen, a ceramic slurry.

We used it at Texas Instruments on our thermal print heads to keep the gold wires ball bonded to the printhead's IC separated and supported inside the trench of heatsink ceramic the IC was mounted on.

Plus, I think the process is the same/similar to that used on headlight dimmer pot windings to hold them rigidly, yet separated in the pot's ceramic trench.