Mediocre AC Solution!
Logistics Pro
Joined: Sep 2002
Posts: 4,411
Likes: 1,016
From: Central KY
I have recently learned that Ford designs these trucks to cycle systems on/off for the purpose of saving horsepower and thereby saving fuel.
There is a Battery Management System that I never heard of before that has sensors on both battery cables. It cycles the alternator and maintains a very minimum charge on the battery. Lots of guys have seen "battery saver" messages on the dash which shut down the radio or other accessories while the engine is off and this happens after just a few minutes in many cases. This is because the battery never gets a full charge to start with due to the BMS.
The A/C compressor is also cycled on/off to allegedly save fuel, which is why guys are seeing the temp at the registers going up/down constantly. This is also why the HVAC system on these trucks can't keep up.
I don't know why Ford thinks that saving 0.003 miles per gallon is worth the huge inconvenience that these "features" cause to owners. But this is the type of crap-tastic engineering that turns people off to your product. I hope Ford is reading this.
There is a Battery Management System that I never heard of before that has sensors on both battery cables. It cycles the alternator and maintains a very minimum charge on the battery. Lots of guys have seen "battery saver" messages on the dash which shut down the radio or other accessories while the engine is off and this happens after just a few minutes in many cases. This is because the battery never gets a full charge to start with due to the BMS.
The A/C compressor is also cycled on/off to allegedly save fuel, which is why guys are seeing the temp at the registers going up/down constantly. This is also why the HVAC system on these trucks can't keep up.
I don't know why Ford thinks that saving 0.003 miles per gallon is worth the huge inconvenience that these "features" cause to owners. But this is the type of crap-tastic engineering that turns people off to your product. I hope Ford is reading this.
Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
I have recently learned that Ford designs these trucks to cycle systems on/off for the purpose of saving horsepower and thereby saving fuel.
There is a Battery Management System that I never heard of before that has sensors on both battery cables. It cycles the alternator and maintains a very minimum charge on the battery. Lots of guys have seen "battery saver" messages on the dash which shut down the radio or other accessories while the engine is off and this happens after just a few minutes in many cases. This is because the battery never gets a full charge to start with due to the BMS.
The A/C compressor is also cycled on/off to allegedly save fuel, which is why guys are seeing the temp at the registers going up/down constantly. This is also why the HVAC system on these trucks can't keep up.
I don't know why Ford thinks that saving 0.003 miles per gallon is worth the huge inconvenience that these "features" cause to owners. But this is the type of crap-tastic engineering that turns people off to your product. I hope Ford is reading this.
There is a Battery Management System that I never heard of before that has sensors on both battery cables. It cycles the alternator and maintains a very minimum charge on the battery. Lots of guys have seen "battery saver" messages on the dash which shut down the radio or other accessories while the engine is off and this happens after just a few minutes in many cases. This is because the battery never gets a full charge to start with due to the BMS.
The A/C compressor is also cycled on/off to allegedly save fuel, which is why guys are seeing the temp at the registers going up/down constantly. This is also why the HVAC system on these trucks can't keep up.
I don't know why Ford thinks that saving 0.003 miles per gallon is worth the huge inconvenience that these "features" cause to owners. But this is the type of crap-tastic engineering that turns people off to your product. I hope Ford is reading this.
Fleet Mechanic
Joined: Sep 2006
Posts: 1,491
Likes: 295
From: Fresno, CA
Correct. Traditional Ford systems (and most others) cycle the compressor based on the low-side refrigerant pressure, which seems to maintain a pretty consistent temperature out of the vents. With previous vehicles I've never noticed temperature swings like these trucks do. Typically when it's really hot out, the compressor runs all the time as it simply can't pull the pressure down low enough to hit the switch.
These trucks cycle is based on air temp leaving the evaporator which is the air that's coming out the vents. The truck actually does cycle it when it's really hot as the temperature it shuts off at is quite high (I believe 47F).
These trucks cycle is based on air temp leaving the evaporator which is the air that's coming out the vents. The truck actually does cycle it when it's really hot as the temperature it shuts off at is quite high (I believe 47F).
Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
Correct. Traditional Ford systems (and most others) cycle the compressor based on the low-side refrigerant pressure, which seems to maintain a pretty consistent temperature out of the vents. With previous vehicles I've never noticed temperature swings like these trucks do. Typically when it's really hot out, the compressor runs all the time as it simply can't pull the pressure down low enough to hit the switch.
These trucks cycle is based on air temp leaving the evaporator which is the air that's coming out the vents. The truck actually does cycle it when it's really hot as the temperature it shuts off at is quite high (I believe 47F).
These trucks cycle is based on air temp leaving the evaporator which is the air that's coming out the vents. The truck actually does cycle it when it's really hot as the temperature it shuts off at is quite high (I believe 47F).
Postmaster
Joined: Aug 2003
Posts: 4,483
Likes: 2
From: Central Texas
Ford has to abide by government regulations on fuel economy as do all automotive manufacturers. They put passenger type tires on the trucks to boost the mpg and a host of other tricks.
Mountain Pass
Joined: Jan 2008
Posts: 231
Likes: 1
From: Silver City, NM
Total BS... I used the very same Radio Shack resistors the same as shown and the AC wont even kick on doing this. I plug it back in and within 15-20 sec its on and blowing cool air again.
I guess the solace is that I only paid 3.29 for the pack of resistors and just had to wait for them to get here. Other wise nothing more than a time waster!
I guess the solace is that I only paid 3.29 for the pack of resistors and just had to wait for them to get here. Other wise nothing more than a time waster!
Mountain Pass
Joined: Jan 2008
Posts: 231
Likes: 1
From: Silver City, NM
Thought I would share this as well.. While this didn't even try to work - This worked and it's Ice Cold...It doesn't read the inside right next to the Condenser. I am going to insert it into he front of the box so that it gets an inside temp reading sop hopfully it wont allow any freezing but doesn't think its ambient temp all the time either! Time will tell!
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thekingofcows
1973 - 1979 F-100 & Larger F-Series Trucks
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