I am hooking up some mechanical guages on my 80 F150 2wd, 300-6. Where is the "dang blamit" water temperature sending unit? I found the oil psi sending unit. Thanks

 

It's on the back of the engine, you have to reach up between the firewall to reach it. Can be a PITA.


From where your oil sender is, you should see a lone wire reaching out toward the back.

You should see it going around to the back of the engine with all it's heat protective plastic on it.

Follow that wire and you should be able to feel it. I doubt that you can see it, unless you stand on your head.

 

I'll check it out during the day light. I do prefer a mechanical guage. As such, some pita is worth it.

Tom

 

It's on the rear passenger side, basically opposite the oil sender unit but a bit higher up. On a van it's staring you in the face as soon as the doghouse comes off, but in a truck it's in never-never land. There's a recent thread about adding a secondary temp sender with several good suggestions... look it up. I'd leave the stock sender as-is and add your mechanical gauge as a duplicate.

 

I just installed an Autometer water temp gauge recently. Read this it should help you out on what to do.

https://www.ford-trucks.com/forums/s...d.php?t=488849

 

I have a parts truck and it has the sender in the heater hose area. It was at the front of the engine. It still had the factory temp guage hooked up.There was a extra port there but I don't know how accuret it would be in this location may read a little cool.

 

I hooked my aftermarket gauge up at that spot because it should be the point where the coolant is the hottest. Its right before it enters the radiator. The coolant should be the coolest after leaving the radiator at the bottom as it goes up into the water pump. Im not sure why some have the sending unit from the factory at the goose neck where it splits off to the heater hose. Mine had a vacuum ported switch that didn't work anymore so I just removed it and replaced it with the sending unit for my aftermarket gauge.

 

Could it be that my 4.9 has 2 temp sending units?

 

Yes. The EFI 4.9 has the same temp sensor that the carb engine does. It sits just below and behind the rear most exhaust port on the passenger side. This is for the dash gauge.
Then, there's a second sensor that is all the way up front, and (if I remember right) is mounted on the thermostat housing. This is the sensor for the fuel computer.

 

I had a problem installing the Autometer mechanical gauge sensor. It was going to bottom out on the cylinder wall if I used the threaded insert that came with it. I soldered an extension on to a pipe bushing to make it set right.