A.C weird problem

[Retci]

Hey guys, its me again. lol

So here's a story for you.

The AC wasn't working. no big deal, it's a 20 year car, it's been sitting a while. might need some Freon? Well it wasn't the Freon. the compressor wasn't engaging. So we tracked the problem down to the switch on the High/lo side that wasn't working. Part's on back order, husband is a mechanic- there's now a manual switch I have to switch to make the compressor engage.

Now here's the fun part. I live an hour from town, so I leave that switch flipped on, after about an hour, my vents accumulate frost and the lines under my hood by the firewall are covered in white thick frost. The vents inside will stop blowing ( I assume it's because everything is frozen, no doubt), even tho I hold my hand up to them and feel cold air.

Google says it's because there moisture in the system. My weather is humid <I live in central Alabama. humid is the name of the game down here>. But that doesn't sound correct?

What are your thoughts, Think Tank?

 

[Pete Deering]

Hey guys, its me again. lol

So here's a story for you.

The AC wasn't working. no big deal, it's a 20 year car, it's been sitting a while. might need some Freon? Well it wasn't the Freon. the compressor wasn't engaging. So we tracked the problem down to the switch on the High/lo side that wasn't working. Part's on back order, husband is a mechanic- there's now a manual switch I have to switch to make the compressor engage.

Now here's the fun part. I live an hour from town, so I leave that switch flipped on, after about an hour, my vents accumulate frost and the lines under my hood by the firewall are covered in white thick frost. The vents inside will stop blowing ( I assume it's because everything is frozen, no doubt), even tho I hold my hand up to them and feel cold air.

Google says it's because there moisture in the system. My weather is humid <I live in central Alabama. humid is the name of the game down here>. But that doesn't sound correct?

What are your thoughts, Think Tank?

You don't have any problem , your system is working fine. The AC lines are cold. You have a few things going on.
1. The line by the firewall with white thick frost is because the outside air is humid and the AC line is cold, you can insulated it.
2. The low side line temperature is below freezing. Some cars have deicing switch ford uses the the low pressure switch to cycle off the compressor. You say you use a manual bypass switch too turn on the compressor. That is the result from your switch.
3.The vents inside vehicle will stop blowing ( I assume it's because everything is frozen, no doubt), you are correct. The Evaporator coil is freezing up , no air flow thru the coil because of the frost on the coil.
4. Get yourself a thermometer ( Wal-Mart or target, cooking section, digital display about $10)stick it the center vent and watch the temperature. What will bring the evaporator temperature up (warmer), keep the the fan speed on 4 ( it will raises the center vent temp (warmer)),also bring in outside air, that will raise(warmer) the center vent temp min of 5 degrees.

 

[CallMeSyd]

Agreed, AC freezing caused by using switch to run the compressor clutch directly. The normal de-icing cycle can not function if you bypass it and run the compressor clutch directly.