68 C20 - were backup lights optional?

[hounddogs!]

I didn't think so, but now I'm wondering.

Backstory: I had the bed blown apart over the winter. As it went back together, I was meticulous about cleaning/painting the light reflectors, doing serious grounds etc etc. Everything's great except the B/U lights.

Fast forward a little while and it's time to track down what the problem is. Fuse is good, trans switch (SM465) is good. Follow the wiring from the trans up to the firewall bulkhead and there's not anything on the inside. The cavities on the female side were empty and the plug down by the NSS was empty as well.

I can't think someone would have gone to the the trouble of removing the terminals, were they not there in the first place?

[ray_mcavoy]

Backup lights became standard equipment on these trucks in 1966. Although there was a backup light delete option (RPO T91 I think) available for trucks that were to be exported outside the US.

Also, the backup light wiring in the under-dash / cab harnesses was configured according to the type of transmission. For example, 3-speeds & automatics had the backup light switch on the column so they didn't have any of the backup light wiring running through the bulkhead connector like the 4-speed did. So someone might have swapped a different cab harness into your truck at some point in the past and got one out of a truck that originally had a 3-speed or automatic.

[hounddogs!]

The auto harness absolutely makes sense. Thanks.

Here's the fun part - it's probably been without b/u lights since before 1971. I don't see my grandfather (the truck's owner 1971-1993) doing a terminal block swap. I sure haven't since '93. Crazy.