HVAC Troubleshooting

[TRaptor69]

Good evening, community. I'm having issues with the HVAC system in my 2011 Screw Raptor and, despite extensive research, I haven't found a similar case. Here's a summary of the problem and the steps I've taken so far:

Problem Description:For the past few months, my A/C has not been blowing very cold, especially during the extreme 116-degree days in Texas.

Steps Taken:

1. Freon and Pressure Checks: I checked the freon levels and system pressures.
2. Resistor Testing: I experimented with resistors (300-390K Ohm).
3. Evaporator Core Cleaning: I performed a deep cleaning of the evaporator core.
4. Additional Troubleshooting: I used Forscan and a temperature gauge for further diagnostics.

Current Diagnostic Trouble Codes (DTCs):

1. B11F0 - Air Intake Damper Position Sensor Additional Fault
   • Symptom: Circuit Short To Ground Or Open
2. U0163 - Lost Communication With Navigation Control Module
   • Note: This might be related to my aftermarket stereo installation, which replaced the SYNC 1 system that stopped accepting Bluetooth. Despite installing a new APIM, the issue persisted for a few weeks.

HVAC System Condition:

• The re-circulation door is broken; I’ve temporarily closed it to improve cooling.
• After removing the blower motor to address the broken piece, I cleaned the evaporator core as thoroughly as possible without removing the entire dashboard. It’s now 90% clean with only some small debris remaining.
• I also cleaned the evaporator temperature sensor and reinstalled it in its original position.
• I installed a new outside air temperature (OAT) sensor, as some users have reported that this resolved similar A/C issues for them.

Current System Readings:

• Low Pressure Side: Stable at 40 PSI; compressor clutch engages properly.
• Evaporator Temperature: At the lowest fan setting, it reads a stable 37-41°F and the compressor cycles correctly. However, as the fan speed increases, the evaporator temperature rises, reaching 61°F at the highest fan setting. At 2500 RPM, the temperature drops only to around 57°F, with the compressor remaining fully engaged and not cycling.

Vent Temperature:

• Lowest Fan Setting: 50-53°F with minimal airflow.
• High Fan Setting: 60-70°F.

Current Suspicion: I suspect that the problem may be related to the thermal expansion valve, which I am planning to replace.

Next Steps: I’m considering getting the entire system evacuated, flushed, and cleaned. I also plan to replace the dryer.

Request for Advice: Although I am not an expert in A/C systems, I would greatly appreciate any advice from those who have encountered similar issues or from experts in A/C systems.



While addressing the A/C problem, another issue has arisen. The airbag light is now on, displaying the code B005D - Short to Ground on the front passenger seat.

Troubleshooting: When I plug in the seat belt connector, clear the code, the airbag light turns and stays off. However, as soon as I unbuckle the seat belt, the airbag light reappears immediately.

I am also happy for any piece of advise regaring that issue.

Thank you!

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[Guardrail]

I never flushed mine, but I did put in a kit like this.

https://www.oreillyauto.com/detail/c/murray-climate-control/air-conditioning---heating/a-c-service-kit/9412599d9a39/murray-climate-control-a-c-service-kit/mry1/muk20037/v/a/119814/automotive-truck-2013-ford-f-150?pos=0

It was Ice cold again

 

[Guardrail]

Also, you might have a bad seat belt retractor?

 

[Meat2022]

I never flushed mine, but I did put in a kit like this.

https://www.oreillyauto.com/detail/c/murray-climate-control/air-conditioning---heating/a-c-service-kit/9412599d9a39/murray-climate-control-a-c-service-kit/mry1/muk20037/v/a/119814/automotive-truck-2013-ford-f-150?pos=0

It was Ice cold again

What is this kit? I had to order a discharge line due to leaking. It will be here Friday. I think once this is replaced I'll be good to go again. I may of over looked it but did you use the ac dye and check it for leaks ? I'm guessing you did with all of the troubleshooting you did.

 

[TRaptor69]

Thank you for your responses. I’ve thoroughly checked for any leaks and found none (UV dye). The kit looks promising and comes with a limited lifetime warranty. However, I did have an issue with the Murray OAT sensor I purchased recently; it failed immediately and triggered an error code. I will have to go back and get a new one.

Given this experience, I’m curious about the performance of the kit so far. How long have you been using it, and have you experienced any issues with its quality and reliability?

I plan to have the A/C system evacuated either today or tomorrow. This will allow me to start swapping out components and flushing the system this weekend.

Regarding the Airbag code, I do think it's related to a faulty sensor inside the passenger SRS. Does anybody know the correct part number? I will try to look it up.

Thanks for the help!

 

[Guardrail]

What is this kit? I had to order a discharge line due to leaking. It will be here Friday. I think once this is replaced I'll be good to go again. I may of over looked it but did you use the ac dye and check it for leaks ? I'm guessing you did with all of the troubleshooting you did.

I didn't use the dye. The system wasn't leaking, it just wasn't cold. I'm not sure sure exactly what service kit I used, It was probably 3 years ago. That's why I said I used a kit "like" this.

 

[Meat2022]

What exactly does that kit do?

 

[Guardrail]

It's a kit for servicing the ac. It comes with a thermal expansion valve, dessicant bag, oil and all the orings you need to change those parts. It's just easier to buy the kit instead of buying all the parts individually.

 

[TRaptor69]

Update: I have completed the replacement of all components included in the kit. The system initially required more R134a than indicated by the label before it began functioning correctly. Currently, the truck's idling RPM is set between 550 and 600, which seems slightly low for achieving an EVAP core temperature of 38°F. When the engine is revved, the temperature gradually decreases until the compressor clutch disengages. At idle, the compressor remains engaged. The pressure readings appear to be within the expected range according to various online charts and tables, with the low side registering at 30-35 psi and the high side at 250-260 psi. Can anybody confirm if these readings are up to spec?

After flushing the evaporator core and two lines, I performed a vacuum test twice, each time for approximately 45 minutes. I then conducted two leak tests; the system maintained a vacuum level of 28-29 inHg without any deviation over a period of two hours.

Although the vent temperatures are still in the 50s, there has been a noticeable improvement in cooling performance since permanently closing the recirculation door. The system now cools significantly better. However, I am seeking insights into why the vent temperatures remain higher than expected, despite the EVAP core consistently maintaining a temperature of 38-40°F.
Could the issue be related to the blend door?

Additionally, the SRS system is still showing an error code: B00D5:13-48 (8B) - Circuit open.

It seems that replacing the entire module may be necessary. If anyone has experienced a similar issue or has any advice, I would appreciate your help.

 

[Guardrail]

The pressures depend on the ambient air temperature