Hi,

I have a 2003 Grand Marquis with about KM 150,000. About 1 month ago when I start my car on the morning and switch on the AC I only get hot/normal air coming out instead of the cold air... This goes on for about 5 min until I hear the click of the compressor and then cold air start coming out normally. I assume that for the first 5 min power does not go to the compressor but not sure how I can check it? Do you have clue about this problem?

Thanks.

 

There's usually a little delay after a cold start but don't think it's supposed to be five minutes. I'm wondering if your refrigerant charge is low enough or a bad low pressure sensor is keeping it off. The switch is attached to the accumulator up near the p/s firewall. Disconnect the plug on the sensor & jump across the terminals with a wire. Then do your cold start & see if the compressor kicks in sooner. It could be just low enough on charge for the low press sw to be kepping it off then as the engine warms up it will increase the pressure in the a/c system allowing the sw to send it's power. I would think that would only apply when the outside temp is below say 75* or the system wouldn't get real cold. If it's none of that I would suspect a PCM reflash or problem in the PCM itself. Also the coolant temp sensor could be bad telling the pcm it's too cold outside & it wont power the a/c. I can get you resistance vs. temperature values if you need to check it or it can be checked with a scan tool cabable of reading both the ECT & IAT. Cornfused yet