Exterior Temperature Gauge "Sticks"

[sirbias]

I have a 2007 Fusion and the external temperature gauge in my climate control panel sometimes sticks. This affects how effectively the car gets to the desired interior temperature. Has anyone had a similar experience? Should I mention this to the dealer before I run out of warranty?

 

Thanks!

 

SIRBIAS

[bartman1]

I have a 2007 Fusion and the external temperature gauge in my climate control panel sometimes sticks. This affects how effectively the car gets to the desired interior temperature. Has anyone had a similar experience? Should I mention this to the dealer before I run out of warranty?

 

Thanks!

 

SIRBIAS

On my 2010, if it is parked in the shade, the exterior temp does not properly register for several minutes. This delays the cool-down of the cabin. I also believe that the exterior temp stays where it is when you shut off the car (I can't prove it though), which means it takes some time to correctly register outside after you start up.

[akirby]

What makes you guys think the outside temperature has anything to do with the interior temperature or the HVAC system?

[FFHdriver]

What makes you guys think the outside temperature has anything to do with the interior temperature or the HVAC system?

I think the HVAC auto mode is adjusted by the outside temperature and other inputs and gets a reading from an outside temperature sensor. If this sensor also sends the same reading to the dash and it's wrong, then the HVAC would be affected.

[akirby]

I think the HVAC auto mode is adjusted by the outside temperature and other inputs and gets a reading from an outside temperature sensor. If this sensor also sends the same reading to the dash and it's wrong, then the HVAC would be affected.

 

The auto HVAC has a separate inside temperature sensor. I'm 99% sure that it doesn't use the exterior temp sensor.

[twiggy144]

The auto HVAC has a separate inside temperature sensor. I'm 99% sure that it doesn't use the exterior temp sensor.

 

Most cars with auto HVAC use the following 4 parameters to command heat, blower speed and vent position: inside temp, outside temp, sun ray cell (on dash near the windshield), and the desired temp set by the driver. A Fusion shop manual would confirm if it does the same.

[DaveM]

I think the HVAC auto mode is adjusted by the outside temperature and other inputs and gets a reading from an outside temperature sensor. If this sensor also sends the same reading to the dash and it's wrong, then the HVAC would be affected.

I doubt that. If I set the temp to 72 it is the job of the air/heat to make my inside 72 degrees. It should measure the inside temp and adjust acordingly just like at home.

[FFHdriver]

I doubt that. If I set the temp to 72 it is the job of the air/heat to make my inside 72 degrees. It should measure the inside temp and adjust acordingly just like at home.

Your home isn't getting lots of outside air to deal with. Most houses don't have auto temperature control only manual settings.

[akirby]

Most houses don't have auto temperature control only manual settings.

 

Every house I know has a thermostat. You set the thermostat to the desired temp and it regulates the hvac to maintain that temperature. That is EXACTLY how the auto climate control works in a car.

 

While it's possible it uses the external temp, I don't see where it's necessary. It knows the internal temp and the desired temp and it adjusts the fan and temperature as necessary.

[FFHdriver]

Every house I know has a thermostat. You set the thermostat to the desired temp and it regulates the hvac to maintain that temperature. That is EXACTLY how the auto climate control works in a car.

 

While it's possible it uses the external temp, I don't see where it's necessary. It knows the internal temp and the desired temp and it adjusts the fan and temperature as necessary.

Most houses I've been in don't have a thermostat that will automatically switch from heating to cooling when needed. You have to tell it that you want the AC or the furnace to operate by a switch on the thermostat. Maybe yours is different. There are thermostats that will do this but they can have a problem with turning on the heat at night in the summer if the house temperature drops, which you may not want or the opposite in the winter. I tried one in a hotel room.

[akirby]

Most houses I've been in don't have a thermostat that will automatically switch from heating to cooling when needed. You have to tell it that you want the AC or the furnace to operate by a switch on the thermostat. Maybe yours is different. There are thermostats that will do this but they can have a problem with turning on the heat at night in the summer if the house temperature drops, which you may not want or the opposite in the winter. I tried one in a hotel room.

 

Well that's different than saying "Houses don't have automatic temperature control". They do, just not for both heating and cooling at the same time.

[FFHdriver]

Well that's different than saying "Houses don't have automatic temperature control". They do, just not for both heating and cooling at the same time.

Sorry I worded that wrong.

[rpreuss]

Every house I know has a thermostat. You set the thermostat to the desired temp and it regulates the hvac to maintain that temperature. That is EXACTLY how the auto climate control works in a car.

 

While it's possible it uses the external temp, I don't see where it's necessary. It knows the internal temp and the desired temp and it adjusts the fan and temperature as necessary.

 

Old tech homes (Most of us live in those), yes, only the indoor thermostat. "Smart" HVAC systems will also use outdoor temperature to PREDICT heating and cooling needs before the indoor temperature is too far off and the system has to overwork to catch up.

 

I have personally noticed, and so have a couple of others, that when on auto, our FFH seemed to be cooling less when we were suddenly driving in the shade. As soon as we were in bright sun, the AC would kick it up a notch (Get colder) and the fan would speed up. Remember, in the FFH, the compressor is electric and the output can be varied. We suspected some kind of light sensor on the dashboard.

 

Also, when it is cold outside and hot in the car (Parked in the sun on a cold day) the system should be able to take advantage of the pre-cooled intake air rather than running the compressor on high to cool the interior. It's all just a matter of a few sensors and computer software.

 

Have you noticed that on cool, humid days, the heat is on and the AC indicator shows the compressor is running to dehumidify the air. Yes, there is a humidity sensor in the system too.

[akirby]

Old tech homes (Most of us live in those), yes, only the indoor thermostat. "Smart" HVAC systems will also use outdoor temperature to PREDICT heating and cooling needs before the indoor temperature is too far off and the system has to overwork to catch up.

 

I have personally noticed, and so have a couple of others, that when on auto, our FFH seemed to be cooling less when we were suddenly driving in the shade. As soon as we were in bright sun, the AC would kick it up a notch (Get colder) and the fan would speed up. Remember, in the FFH, the compressor is electric and the output can be varied. We suspected some kind of light sensor on the dashboard.

 

Also, when it is cold outside and hot in the car (Parked in the sun on a cold day) the system should be able to take advantage of the pre-cooled intake air rather than running the compressor on high to cool the interior. It's all just a matter of a few sensors and computer software.

 

Have you noticed that on cool, humid days, the heat is on and the AC indicator shows the compressor is running to dehumidify the air. Yes, there is a humidity sensor in the system too.

 

There is no humidity sensor. It normally runs the A/C to dehumidify the air unless the temp is below 40. There is a sunlight sensor that compensates for sunlight. Other than that it's just responding to changes in interior temperature.

 

I've seen outside temp sensors on boilers in the north but in the south where we use gas and electric forced hot air there is no outside temp sensor necessary.

[rpreuss]

There is no humidity sensor. It normally runs the A/C to dehumidify the air unless the temp is below 40. There is a sunlight sensor that compensates for sunlight. Other than that it's just responding to changes in interior temperature.

 

I've seen outside temp sensors on boilers in the north but in the south where we use gas and electric forced hot air there is no outside temp sensor necessary.

 

I have never seen the humidity sensor, but on page 239 of the 2010 Fusion Hybrid manual, fuse #37 is a 10 amp labeled "Humidity sensor". I just assumed it was used by the climate control, since on damp day, the AC light comes on, and on dry days, it does not. When trying to WARM the vehicle. (Set point is higher than the ambient internal temperature.)

[DaveM]

I have never seen the humidity sensor, but on page 239 of the 2010 Fusion Hybrid manual, fuse #37 is a 10 amp labeled "Humidity sensor". I just assumed it was used by the climate control, since on damp day, the AC light comes on, and on dry days, it does not. When trying to WARM the vehicle. (Set point is higher than the ambient internal temperature.)

I wonder if it is on the regular Fusion and if not than I bet it has something to do with keeping the humidity low on either the elec. motor or the battery pack or both.

[DaveM]

I have never seen the humidity sensor, but on page 239 of the 2010 Fusion Hybrid manual, fuse #37 is a 10 amp labeled "Humidity sensor". I just assumed it was used by the climate control, since on damp day, the AC light comes on, and on dry days, it does not. When trying to WARM the vehicle. (Set point is higher than the ambient internal temperature.)

I wonder if it is on the regular Fusion and if not than I bet it has something to do with keeping the humidity low on either the elec. motor or the battery pack or both. I just downloaded the reg. Fusion manual and there is NO HUMIDITY sensor at any fuse location and fuse 37 is empty so it has to be something to do with the Hybrid part of the car and not the Air conditioner.

[rpreuss]

I wonder if it is on the regular Fusion and if not than I bet it has something to do with keeping the humidity low on either the elec. motor or the battery pack or both. I just downloaded the reg. Fusion manual and there is NO HUMIDITY sensor at any fuse location and fuse 37 is empty so it has to be something to do with the Hybrid part of the car and not the Air conditioner.

 

Hmmm. Ford makes a big deal in their engineering videos about how they "Use cabin air to cool the batteries". I wonder if they want to keep the humidity at a controlled level.

 

Of course, if you are like me, and it is a nice day, I shut off the climate control, open the windows and the moon roof, and feel young again. And if it is a cool day at the shore, (that's the Jersey Shore) the humidity can be quite high.

 

But, if it is unique to the FFH, than maybe it has something to do with cooling the batteries.