[compsur]

Reaching out to all the 64 GTO experts here. I want to install a rear window defogger in my recently purchased 1964 GTO. I recently purchased a switch that was advertised as fitting both 1964 and 1965 GTOs. However, being a purist that I am, I want to be certain this switch and wiring are correct for my ’64 and not a ’65.

When I checked my parts book, I found that the 1964 switch carries part number 97756544, while the 1965 switch is listed as 9780999. The fact that Pontiac assigned different numbers—and that the 1965 switch was more expensive at the time—leads me to believe there are differences in the setup between the two years.

My assumption is that the 1964 switch may have used a power lead that plugged directly into the fuse box, similar to the full‑size Pontiacs of that year. The 1965 version may instead connect through the accessory harness. At any rate, I’ve attached photos of the switch I picked up, and I’d greatly appreciate someone’s expertise in confirming whether it’s truly correct for a 1964 application or does it cross exactly with 1965,
Thank you in advance for your help.