They look like coolant temp sensors, but each has a different connector housing.

 

The appear to both be coolant temp sensors.

One goes to the PCM for monitoring
One goes to the cluster for the gauge

 

Any idea why they have slightly different connectors, or what the part number for each is? I can't find info on them anywhere.

 

Different connectors may be to keep the assemblymen from hooking up the wrong wires would be my guess.

 

Agreed with this analysis

 

https://www.tascaparts.com/oem-parts...bC12Ni1nYXM%3D

They show #7 and #8 in the diagram but doesn't show two part numbers

Coolant Temp Sensor - Ford (3F1Z-12A648-A)

 

One is a coolant temp sensor, the other is a cylinder head temp sensor.

https://www.tascaparts.com/oem-parts...or-xl3z6g004aa

 

Yep. I too can only find one temp sensor in various places and diagrams. I found a cylinder head temp sensor on RockAuto that looks to have a matching connector to one of them, but I haven't found anything that shows that sensor being in the lower intake.

Since getting this truck in a trade and working on it, I am rapidly remembering why I steered away from Fords over 35 years ago. They make the simplest things so damn frustrating.

 

From what I saw the head temp sensor is on the back of the head by the bell housing

 

Yeah, that's what I've seen also.

Can't find anything online or in the manuals that references these two sensors in the lower intake. I'm sure they are coolant, and like you mentioned feed the cluster and PCM. Just never seen two different undocumented sensors to do it.