Attached is a picture of a ?typical? Aftermarket version of the Felt Battery Washers. Note that these are usually available in a pack of two, one Red (for the positive terminal), and one Green (for the Negative terminal). These Felt washers have usually been impregnated with some type of ?rust preventative? substance.
A look into the Ford Felt Battery Washers has revealed the following :
ASSEMBLY LINE FELT WASHERS
Standard Part Number 374043-S (Engineering/Identification Number ?) appears in the Mustang Electrical Assembly Manuals in each year of 1964.5/65, 1966, 1967 and 1968. Accompanying each Illustration of same is a note saying that each washer should be saturated ?with M-7C12 Rust Preventive Before Installing Washer to Terminal Post??. It further notes that this should be on ?Positive Terminal Only?. To me, this implies that the Assembly Line Felt Washers were furnished ?Dry?, and Rust Preventive only applied when installing. Additionally, no Price is listed for 374043-S, which also implies that these were Assembly Line items only, and not available as a Service Part.
SERVICE PART FELT WASHERS
In late 1961 (I say ?late? because it does not appear in the 1961 Ford Parts & Accessories Catalog, printed in January of 1961), Ford introduced Part Number C1AZ-10A717-A, ?Washer-Battery Terminal Corrosion Arrestor, 11/16 I.D., Felt. Oil Impregnated? ; quantity required ? 2.TYhis Part and its description appear in each year?s Parts & Accessories Catalog from 1962 through 1967 (and possibly more), as well as in the 1960-68 MPC and the 1965-72 MPC. Interestingly, they do not appear in either the 1973-79 MPC, or in the 1980=89 MPC, implying that Part C1AZ-10A717-A was made obsolete (discontinued) in late 1972 or early 1973 (I have not checked my OSI catalogs yet).
This Felt Washer was available in a 2-pack in 967 for $0.58. Neither the Assembly Manual nor the Parts & Accessories Catalogs, nor the MPC?s show what color the Felt was. Also of interest is the fact that the Assembly Manuals all note ?Positive Post Only?, while all applications in the Parts & Accessories Catalogs and MPC?s show that a quantity of 2 is required.
Finally, it is noteworthy that all the Service Part Felt Washers were Oil Impregnated, while the Assembly Line ones were apparently furnished dry, and were only impregnated with a Rust Preventive when installed.
Hope this helps,
Bob