Ac evaporator part hot part cold

[leroyd92]

I have a 97 expedition. New pump, hose,dryer and properly charged. Pump seems to short cycle or cycle on-off rather quick.

I cut a 4" hole behind the glove box to see if my bend door was broken but it's fully functional. The ac evaporator only has cold air passing through at the very bottom. The rest of it has hot air (regular ambient temp ) blowing by.

Is this normal? Is this why i have no cold air?

 

[HerrStig]

Sounds like a clogged expansion valve, or an undercharge.

 

[mk378]

This would be an orifice tube system, so no expansion valve. But the tube can get clogged. While the system was open for repairs, was it checked? Since it's only about a $2.00 part it is also common to just replace them during any major work.

The first thing I would think though is that these are classic symptoms of being undercharged. You likely have a leak. Have someone with a machine recover the charge and weigh how much came out.

The evaporator needs to fill up with liquid refrigerant (that is in the process of evaporating) for the whole thing to become cold. If there isn't enough refrigerant in the system, only part of it gets cold.

 

[Chris142]

Low on charge.

 

[JC1]

Originally Posted By: leroyd92
I have a 97 expedition. New pump, hose,dryer and properly charged. Pump seems to short cycle or cycle on-off rather quick.

I cut a 4" hole behind the glove box to see if my bend door was broken but it's fully functional. The ac evaporator only has cold air passing through at the very bottom. The rest of it has hot air (regular ambient temp ) blowing by.

Is this normal? Is this why i have no cold air?


Did you use a set of manifold gauges when you recharged it?

 

[leroyd92]

The vehicle was charged in savings works' mechanic's who maintain our 90 vehicle fleet.

 

[DSparks]

Accumulator and suction line going back to compressor should all be cold too
..
Sounds like its undercharged still....I would put both low side and hi side gauges on it to make sure the orifice tube or possibly evaporator arent restricted...was the system open to the atmosphere at all and was it vaccumed b4 recharging?

 

[DoubleWasp]

Undercharged. Half cold, half not is a dead giveaway.

Charging by pressure is a very testy process on some trucks. If you do not create the perfect cooling environment for the condenser, a false charge is easy to run into.

Mist the condenser with a garden hose. If the system gets even warmer, you are almost definitely undercharged.