Coolant Temp sender/gauge question

[iracemine]

ok, this sounds like a good place to ask. what the hell makes the fan kick on and off??? I don't see anything attached to the clutch so I am assuming it feels the heat coming from the radiator and something inside expands and grabs the shaft and on it goes??????????

 

[Tail_Gunner]

ok, this sounds like a good place to ask. what the hell makes the fan kick on and off??? I don't see anything attached to the clutch so I am assuming it feels the heat coming from the radiator and something inside expands and grabs the shaft and on it goes??????????

There is a bi-metallic spring or coil on the front of the fan clutch facing forward. It is sort of like the coil spring in a thermostat in a house. As the temperature changes, the coils expands or contracts. Because it's wound around a screw, it turns a screw CW or CCW depending if it's warming or cooling. Inside the fan clutch there is a fluid that flows around inside the clutch. As the airflow from the radiator heats the coil, it turns the screw closed. That shuts off the flow of fluid locking the fan clutch, forcing the clutch to stop free-wheeling and to lock up. When the clutch is locked up it is forced to turn the fan under power forcing more air through the radiator.

Usually, when these things engage, you'l hear it because it sounds like a proppeller powered airplane roaring under the hood when you're going down the road.

 

[nswsparky]

A little off topic, but where are you mounting the sender for the aux temp gauge.

 

[Tail_Gunner]

A little off topic, but where are you mounting the sender for the aux temp gauge.

On the 4R100 trans behind a 7.3, there is a pressure test port on the left side of the transmission. It has a plug installed in it. You can remove the plug and screw the temp sensor in right there.

 

[nswsparky]

On the 4R100 trans behind a 7.3, there is a pressure test port on the left side of the transmission. It has a plug installed in it. You can remove the plug and screw the temp sensor in right there.

I meant the engine coolant temp sender.

 

[BIG JOE]

I meant the engine coolant temp sender.

Another location would be:

Looking down, on the waterpump, on the right side below the thermostat.. is a unused, plugged, threaded port.

Joe

 

[Hooper]

Sorry for the misleading signature, bought the 02 F350 about a year ago and just didn't add it yet.
Installed a new fan clutch and made a run to Lake Hemet. Still didn't get the
fan clutch to engage but it was pretty cold out (for us) and the gauge didn't
move above the 1/2 way point.
I'll try it again when things warm up but I think the fan clutch was the problem and not having a proper coolant temp gauge.
Thanks for the input.

 

[RSG]

Just fyi, I put the coolant temp gauge on a spare port on my filter housing. That is about 8 or 10" of hose from the water pump so it might read a degree lower than actual but very convenient -- drilled a hole thru the AFE box and screwed the rtd into the port that was hitting the AFE box...

On a 1000 mile trip w big trailer load this week it would run 200-210 depending on the grade (outside was 15F - 45F; 203F thermostat). Yeah, like TG says, when the fan clutch kicks in you will know it, sounds like you're combining wheat or something up front.

 

[BIG JOE]

FWIW ?

If you mount(ed) the coolant filter assembly on to anything Non-metal (like the intake snorkel, like per Dieselsite's instructions).... and use the unused port for a temp sensor ? yul need to Ground the sensor, to a metal ground..... to git the gauge to work.

Don't ask me how I figured that out