What is this component under my hood?

[Andyanaj0nes]

60 series 2F petrol engine with a 4 speed manual. What is this part with the faded white label on top? It’s on the drivers side.

Thanks
Andy
Formerly Captain obvious

 

[DrRock]

Carb fan. Designed to cool the carb after shut down

 

[Andyanaj0nes]

Carb fan. Designed to cool the carb after shut down

Carb fan. Designed to cool the carb after shut down

Wow! That was fast. Thanks man! It’s probably in my FSM, but I never thought to look there

 

[Everhix]

Wow! That was fast. Thanks man! It’s probably in my FSM, but I never thought to look there

Interesting, my 1988 has this same fan, but a 3F engine. No carb. Original engine as far as I know.

 

[Lead Head]

Interesting, my 1988 has this same fan, but a 3F engine. No carb. Original engine as far as I know.

It serves the same purpose on a 3FE - it cools the fuel rail and fuel injectors down after you shut the vehicle off to stop the exhaust from cooking them. Mine will turn on pretty much every shut down if it's 85+ degrees outside, especially if you just got off the highway with the AC on. On cooler 70-75 degree days, it is much less likely to run.

 

[Everhix]

It serves the same purpose on a 3FE - it cools the fuel rail and fuel injectors down after you shut the vehicle off to stop the exhaust from cooking them. Mine will turn on pretty much every shut down if it's 85+ degrees outside, especially if you just got off the highway with the AC on. On cooler 70-75 degree days, it is much less likely to run.

That makes sense. I need to check the power to it. Never heard it come on before and it is definitely hot enough.

 

[bhsdriller]

It operates based on a temp sensor in the manifold not ambient temperature.

There's lots of threads discussing it and showing location of that sensor. Most of the time the wire on the sensor breaks off then it doesn't work. What you can do for an easy fix is just run that to a ground instead of the sensor.
The fan will then just run every time you turn the key off for 20-25 minutes.

Only if you really want it working. If it's starting fine on warm days after shutdown than don't worry about it

 

[Everhix]

It operates based on a temp sensor in the manifold not ambient temperature.

There's lots of threads discussing it and showing location of that sensor. Most of the time the wire on the sensor breaks off then it doesn't work. What you can do for an easy fix is just run that to a ground instead of the sensor.
The fan will then just run every time you turn the key off for 20-25 minutes.

Only if you really want it working. If it's starting fine on warm days after shutdown than don't worry about it

Good advice. Thanks.

 

[Lead Head]

That makes sense. I need to check the power to it. Never heard it come on before and it is definitely hot enough.

Look at the back of the rear exhaust manifold. The heat shield near the rear should have a sensor bolted into it, with a single wire going to it. Start the truck, let it run for a minute, then turn it off. If you connect a ground wire to that sensor, the fan should turn on.

 

[Everhix]

Good advice. Thanks.

I’m guessing it will turn off on its own due to the heat sensor?

 

[Everhix]

Look at the back of the rear exhaust manifold. The heat shield near the rear should have a sensor bolted into it, with a single wire going to it. Start the truck, let it run for a minute, then turn it off. If you connect a ground wire to that sensor, the fan should turn on.

Ok. I will check that this weekend. I assume it shuts off when it cools?

 

[Everhix]

Ok. I will check that this weekend. I assume it shuts off when it cools?

Okay. Sorry for a dumb question! I reread the above. Temp sensor will shut if off. Going to try the ground wire this weekend and see what happens. I appreciate the help.

 

[Lead Head]

Okay. Sorry for a dumb question! I reread the above. Temp sensor will shut if off. Going to try the ground wire this weekend and see what happens. I appreciate the help.

The fan is controlled by the temperature sensor and a small control box inside the vehicle. Whenever you turn the key off, a ~20 minute timer is started inside the control box. If the temperature sensor exceeds the threshold (212°F), it grounds out the wire. The control box will see that the wire has been grounded, and turn the fan on.

It will then run the fan for about 20 minutes, or until the temperature switch drops below the threshold and opens back up. Whichever occurs first.

So to test, you need to briefly run the engine to "set" the timer, and then you can test it by grounding out that sensor.

Note: The fan will only activate if the key is off.

 

[bhsdriller]

I’m guessing it will turn off on its own due to the heat sensor?

Didn't realize you had a 3F fuel injected but they might operate the same as a 60 which i'm familiar with.

No, with what I described you're taking the heat sensor out of the equation. The wire that connects to it, instead of wiring it to the sensor you ground it.
Doing this it doesn't matter temp, it will just always run for the 20 or so minutes anytime the key is turned from on position to off.

 

[Everhix]

Didn't realize you had a 3F fuel injected but they might operate the same as a 60 which i'm familiar with.

No, with what I described you're taking the heat sensor out of the equation. The wire that connects to it, instead of wiring it to the sensor you ground it.
Doing this it doesn't matter temp, it will just always run for the 20 or so minutes anytime the key is turned from on position to off.

Going to get this done this weekend. Thanks

 

[Everhix]

The fan is controlled by the temperature sensor and a small control box inside the vehicle. Whenever you turn the key off, a ~20 minute timer is started inside the control box. If the temperature sensor exceeds the threshold (212°F), it grounds out the wire. The control box will see that the wire has been grounded, and turn the fan on.

It will then run the fan for about 20 minutes, or until the temperature switch drops below the threshold and opens back up. Whichever occurs first.

So to test, you need to briefly run the engine to "set" the timer, and then you can test it by grounding out that sensor.

Note: The fan will only activate if the key is off.

Okay. You guys are awesome. After all the great advice I located the issue. Seems my temp sensor is bad because the wire to it was intact. I unhooked the wire from the sensor and grounded it, as you guys advised, and now the fan is blowing steady. Thanks!