Ac blowing at 55 degrees....

my ac leaves a puddle of water under the truck when running. What does that mean?

 

That means it's working friend !

 

Not necessarily. Some KW models have an electronically actuated heater control valve which has a tendency to go tits up, and it'll have the same effect.

 

It's from your evaporator coil. Moisture is the byproduct of the heat exchanging from the coolant in the coil to the ambient air around it.

 

Does that mean that the coil should be replaced? Thank you

 

No

 

No. Although cleaning off the outside wouldn't be a bad idea. That creates an environment where mildew can thrive. They have an anti mildew spray which I can't remember the name of offhand, but I've only ever used it reactively... don't know how well it works as a preemptive measure.

 

Are you using the recirculate air feature...that will help keep the air cooler.