2002 Mercury Grand Marquis Q&A
2002 Mercury Grand Marquis Question: How do I check to see if a relay is bad?
First and foremost, check your pressures for your A/C system, because if the refrigerant is low, the A/C compressor never be commanded to operate by the Climate Control Computer. here is a good check sheet for inspecting why your A/C does not cool properly, it also includes your climate control module and pulling codes from that as well. You have a pretty modern car and the A/C system has it own computer controls with sensors etc. http://repairpal.com/air-conditioning-diagnosis - dandd