I would very much appreciate some help with my weird air conditioning problem. My air is nice and cool but as soon as i accelerate it cuts out then resumes after I let off on the gas? It also happens when climbing a hill and the engine is loading. I have a 2001 Ford Lariat F150 with a 5.4 litre engine. I anyone has had a similar problem I could use some advice! Thanks in advance.

 

It could need a clutch adjustment as I mention in this post. As you give it more gas the clutch starts to slip.
https://www.f150online.com/forums/19...-ac-issue.html

Ron

 

Have you checked the R134 pressure? You can buy a fill kit guage and the fluid at any auto parts store. the low pressure connector is located on the passenger side below the firewall relay.

 

It is NOT the refrigerant charge level problem.

You need to distinguish between two likely problems:

1) Airflow defaults to the defroster due to a system vacuum leak during periods of low manifold vacuum..

2) Airflow remains on the panel vents but looses cooling (usually needs a shim adjustment).

It could be either (or both, even).

 

The most common source of the vacuum leak are the small hard vacuum lines behind the battery.

 

Thanks to all who responded to my query! I shall investigate all suggestions and hopefully one will solve my problem!

 

My F150 does exactly what you list in your "first symptom." Is the vacuum leak you mention contained within the cooling system or would it have an effect on the performance of the motor? I ask this because my truck has done this since I purchased it but I 've never paid too much attention to it. However, thinking back on it, I have always had an occasional miss that comes and goes.

 

I had the exact same thing happen to me (#1 below). It was a leak that I had a mechanic change for me (very easy for them). I think it only cost me like $60. It got so bad that eventually it just defaulted to defrost (not good in summer...haha). Ever since the leak fix it's been great.