C2-66 stop light capacitor

[Larry Rosamond]

Can a reasonable facimile be "manufactured" from a similar can type capacitor? Actually, I'd buy a real one if someone knows where it is. It seems to me that it would be a fairly simple task to use a similar capacitor and change to an inline connector, resulting in a fairly accurate substitution. I know nothing of the microFarad (or any other pertinent electrical specs, for that matter) of this item or the feasibility of this suggestion. Are any of the other capacitors on the mid-years likely candidates? Comments and suggestions are appreciated.

Thanks and regards, Larry

[Joe L.]

Re: C2-66 stop light capacitor

Larry----

The original capacitor (condensor) used for this application was GM #3854624. It was discontinued by GM almost 25 years ago, so finding an NOS example will not be too easy. Used examples might be around, though, as this capacitor was used on other cars, too.

However, you are correct in that it should not be too difficult to make up a suitable replacement that's similar to the original. The GM #3854624 was a metal-cased capacitor with a spot-welded-on bracket. It was similar in configuration to the type used in pre-75 point type ignition systems. Most of the radio-interference supression capacitors were of 0.5MFD rating and I expect that the 3854624 was also. You MAY be able to make up a suitable replacement from a GM #477371 which is still available from GM for about 12 bucks, list. I am NOT promising that one can be made up from this unit, but I think that it MAY be possible.

[Jack H.]

Re: C2-66 stop light capacitor

The brake light capacitor, PN 3854624, was unique to '64-67 Corvette vs. Chevy passenger cars of the era and the catalogs I checked show it as NA.... The factory original part was a wax foil component with steel mounting band/bracket with insulated axial leads trimed to length for the application and appropriate connectors. Spec is: 0.47 uF, 200 VDC, 10% tolerance.

If one isn't interested in factory concours authenticity detail, this is a piece of cake to functionally duplicate. All you need is any NON-POLAR capacitor (polyester, polypropylene or metal film are today's equivalents to wax foil construction and they do NOT have a useage/shelf life) of similar specs.

The 0.47 uF storage value is a standard/common rating. A tolerance of 10% is wide/sloppy and just about anything sold today meets this! 200 VDC specs the peak working voltage the part can withstand before breakdown (200V of DC) and that too, isn't out of the ordinary. Hey, you could go 250, 300 and so on, but my take is the original 200 VDC was probably OVERKILL for essentially a 12 VDC automotive application.... Depending on construction technology (results in size or printed circuit board real estate 'footprint') catalog prices are $2-14 at qty one. Radio Shack can fix you up!