The air-conditioning (AC) system on a Ford F150 V6 will normally remain charged and in good working order for years, but you will need to troubleshoot the system if you notice the AC is not working properly, especially if it is operating colder than usual. There are several problems that cause a malfunctioning AC system.
Open the hood of your Ford F150 and locate the low-pressure line of the AC system, which is a steel tube that runs from the AC system to the firewall. The steel tubing is larger than any other tubing under the hood and will have a blue cap on the line near the firewall.
Remove the blue cap covering the low-pressure valve.
Connect the pressure gauge to the low-pressure valve.
Check the pressure on the gauge. The pressure should be in the green range. If it is not, then there is a leak in the system or the system needs to be recharged.
If the pressure is within the green band range on the gauge but your AC system does not blow cold air, then your compressor may have failed and needs to be replaced.
