Where's the plug?

About 2 months ago, I pulled the stereo head unit from my 2000 sr5 4wd. Shortly after, covid-19 broke out and I started working from home. Projects mounted and the truck audio got bumped. Long story short, I forgot how many wires plug into the back of the head unit. Does anyone know the number of wires (i.e. white plastic bundles) that plug into the head unit?

Second question, if there are 2 bundles that plug in (and I think that there are), where do those bundles go, if you were to trace them from the head unit backward? I ask because the one that I think should be there has disappeared. I've torn a lot of my dash apart and can't find that bundle of wires anywhere. Any help is appreciated.... photos are welcome.

 

Mystery Solved: I decided to put everything back together, skipping the supposed 2nd plug. It turned out that once the instrument cluster was reinstalled that the stereo began to work, meaning that it must have relied in part on the wiring of the instrument cluster.