F250 AC fuse question

[CompOrange04GT]

So as some may/ may not know F250s have a “ lock” on AC if you idle.

If it’s under 32 degrees it won’t let you run ice cold AC at all. It stays at mid temp.

For any mechanics “, is there a fuse that controls this or something else? I idle for 10-12 hours a day, and regardless if it’s 29 degrees outside I want AC inside lol.

I’ve researched and researched and can’t find. A thing

 

[Zemedici]

What years the truck?

If it’s in drive does it blow cold? Like drive but parking brake on / brakes applied?

If so just bring some wheel chocks with ya lolol

 

[Vinnie_B]

A/C Request

** When the customer directly inputs an A/C request into the HVAC control module, the module sends the request to the GWM over the MS-CAN . The GWM sends the request to the PCM over the HS-CAN1 .

** When an A/C request is received by the PCM , the A/C clutch relay is engaged when all of the following conditions are met:

• Excessively high or low refrigerant pressure from the A/C pressure transducer is not detected.
• Ambient air temperature is above approximately 32.0°F (°C).
• Engine coolant temperature conditions are within normal parameters.
• Evaporator temperature is above approximately 33.8°F (1°C).
• a Wide Open Throttle (WOT) condition is not present.
• Battery state of charge conditions are within normal parameters.
• the PCM does not detect temperatures from the Mass Airflow/Intake Air Temperature sensor that does not correlate with other temperature sensor readings at ignition ON. (Most Mass Airflow (MAF) sensors have an integrated Intake Air Temperature (IAT) sensor).

Compressor control and the evaporator temperature are a function of many parameters, not just a straight on/off, to avoid freezing the evaporator. The PCM monitors multiple temperature sensors for correlation including, but not limited to, AAT, CACT, CHT, ECT, IAT, IAT2, MAF, MAPT, TCB and TCIPT Parameter Identifications (PIDs) (as applicable). The PCM runs this logic after an engine off and a calibrated soak period of 6 to 8 hours. This soak period allows the Ambient Air Temperature (AAT) sensor and the other temperature sensors to stabilize and not differ by greater than a calibrated value, typically 18ºC (32.4ºF). If a temperature sensor input is found to be reporting a temperature imbalance the PCM does not allow the A/C clutch to engage.


Lightning FastElectrical Automotive Repair LLC
PM Me or [email protected]
Website: Lightning Fast Electrical Automotive Repair LLC
Remote or Local (On Site) Technical Repair

 

[CompOrange04GT]

What years the truck?

If it’s in drive does it blow cold? Like drive but parking brake on / brakes applied?

If so just bring some wheel chocks with ya lolol

19

Once I drive about 1/2 mile it’ll blow cold like I just left site. Digital temp gauge jumped from 28 to 52 and AC kicked on

 

[CompOrange04GT]

A/C Request

** When the customer directly inputs an A/C request into the HVAC control module, the module sends the request to the GWM over the MS-CAN . The GWM sends the request to the PCM over the HS-CAN1 .

** When an A/C request is received by the PCM , the A/C clutch relay is engaged when all of the following conditions are met:

• Excessively high or low refrigerant pressure from the A/C pressure transducer is not detected.
• Ambient air temperature is above approximately 32.0°F (°C).
• Engine coolant temperature conditions are within normal parameters.
• Evaporator temperature is above approximately 33.8°F (1°C).
• a Wide Open Throttle (WOT) condition is not present.
• Battery state of charge conditions are within normal parameters.
• the PCM does not detect temperatures from the Mass Airflow/Intake Air Temperature sensor that does not correlate with other temperature sensor readings at ignition ON. (Most Mass Airflow (MAF) sensors have an integrated Intake Air Temperature (IAT) sensor).

Compressor control and the evaporator temperature are a function of many parameters, not just a straight on/off, to avoid freezing the evaporator. The PCM monitors multiple temperature sensors for correlation including, but not limited to, AAT, CACT, CHT, ECT, IAT, IAT2, MAF, MAPT, TCB and TCIPT Parameter Identifications (PIDs) (as applicable). The PCM runs this logic after an engine off and a calibrated soak period of 6 to 8 hours. This soak period allows the Ambient Air Temperature (AAT) sensor and the other temperature sensors to stabilize and not differ by greater than a calibrated value, typically 18ºC (32.4ºF). If a temperature sensor input is found to be reporting a temperature imbalance the PCM does not allow the A/C clutch to engage.


Lightning FastElectrical Automotive Repair LLC
PM Me or [email protected]
Website: Lightning Fast Electrical Automotive Repair LLC
Remote or Local (On Site) Technical Repair

So.. is there a bypass ?

 

[Vinnie_B]

So.. is there a bypass ?

No......... not really because its controlled by the PCM! Its mainly due to the AAT sensor. I personally wouldnt advise a work around due to liability reasons.......sorry!

 

[Morgan]

Perhaps you locate the AAT and wrap it in one of those disposable hand/glove heaters.

Though that statement about an aggregate temp across numerous sensors may foil this idea.

 

[BLOWN PONY]

What the hell do you do for a living where you sit 10-12 hours a day in an idiling truck?

 

[CompOrange04GT]

What the hell do you do for a living where you sit 10-12 hours a day in an idiling truck?

Federal emissions in the oil field.

Normal emissions test is 4 hours.

Some days I do 2.

Sometimes the engine isn’t ready so days are longer while I wait.. So I park on site, truck doesn’t move until I’m done.

Have had plenty of 17 hour days where the truck didn’t move. Just sat at idle

 

[BOOGIE MAN]

Why do you want ac if it's 32 degrees outside? Crack a window....

 

[CompOrange04GT]

Why do you want ac if it's 32 degrees outside? Crack a window....

Today I was testing a 2370 horsepower caterpillar engine.

They are loud as shit. Lol. I have to be parked right beside them

 

[BOOGIE MAN]

Today I was testing a 2370 horsepower caterpillar engine.

They are loud as shit. Lol. I have to be parked right beside them

Fair enough, I knew you'd have a reason but it just had to be said

 

[Junior00]

Honest question, do you really need the compressor on at that temp. Adjusting the temp down and pulling outside air into the cabin doesn’t provide cool enough air?

 

[CompOrange04GT]

Honest question, do you really need the compressor on at that temp. Adjusting the temp down and pulling outside air into the cabin doesn’t provide cool enough air?

I have equipment in the truck that gets hot.. I use the AC to keep it cool essentially.

Days like today I actually had to roll down the window to cool down the equipment… and listen to a loud ass engine.

Throw in diesel regen smell too it blows sometimes

 

[BLOWN PONY]

Federal emissions in the oil field.

Normal emissions test is 4 hours.

Some days I do 2.

Sometimes the engine isn’t ready so days are longer while I wait.. So I park on site, truck doesn’t move until I’m done.

Have had plenty of 17 hour days where the truck didn’t move. Just sat at idle

10-4!
Bet the old ball cooler vents would be nice during the summer. LOL