03 Expedition A/C Problem

[daveplot]

On my 03 Expedition the air conditioning isn't cooling. My first thought was to get a recharge can from the auto parts store. But when I did that, and checked the pressure with the built-in gauge, the PSI were in the correct range, based off the chart on the can, so no recharge was needed.

The compressor sounds like it's kicking on and off, is that normal? While in the truck it sounds like a wooshing, then silence, then wooshing, every few seconds.

What else could i look at before taking it into Ford?

Thanks

 

[ELVATO]

How fast is it turning on and off? It should stay on for a good amount of time (maybe 30 secs or longer).

Did you compensate for ambient temperature? Not sure if the can has the chart for that. If you search around under my posts, I posted a graph of the pressure you should be seeing based on the ambient temperature.

 

[daveplot]

It was cycling about every 5 seconds, I could see it on the pressure gauge too.

I'll double check the pressure tomorrow, and bring back the readings I was getting. The chart the can had was based off ambiant temperature.

Based off this post, http://expeditionforum.com/showpost.php?p=31046&postcount=3 does the truck need to be up to operating temperature to check the pressure? I checked it when the engine was cold.

Thanks

 

[daveplot]

When I checked it yesterday it was about 55psi when the compressor was on, and the engine was cold. Ambient temperature was about 75.

 

[joezek]

55 sounds high for the low pressure side of the system. Mine runs 35 low side and 210 high side. You may be overcharged right now.

Was it cycling on/off before filling the freon? Is the air temp in the a/c vents ambient or is it possibly blowing hot air from the truck heat system? If you have rear a/c, is it blowing colder? Sometimes there's a blend door that quits working and forces the a/c to blow hot air that's sucked in through the heater portion of the box instead of from the cold air part of the box.

 

[ELVATO]

Make sure to follow all the directions outlined in the linked post.

There is a high and low pressure shutoff switches. If the pressure is too high (too much refrigerant) or too low (not enough), the compressor will just cycle on/off.