Hey guys, I'm new to the F150 Forum, so this is my first post! As a quick introduction, I recently bought a '93 F150, Manual, with the 302 V8, for my fiancee, and had to do some engine work on it to get it "up to snuff". As I was putting it back together, I noticed that one of the temperature sensors was missing. The connector is still there, but the hole for the sensor has been plugged. Is this done on purpose on these pickups, or should I reinstall a new temperature sensor? In the picture it is the part labeled "12A648". Thanks in advance for your help!

 

Yes you are definitely supposed to have that.
The 10884? something looks to be the temp sender for the dash gauge.
The 12A648 is the sender to tell the computer what temp the motor is at. Without it the engine management system is likely to stay in 'open loop' which is not desirable for a lot of reasons - fuel economy being a big one.