Just because the air blows does not mean the compressor is running it means the single dual shaft fan motor is running, this motor turns the outside fan "a condenser" and the inside blower "an evaporator"...these A/C units are tough little guys...Many are rotary compressors...89% of the time when what you describe happens its because the [b]compressor will not run, the most probable cause I see when working on them is a [b]thermostat problem...
Often I find a burned wire on the back of the [b]temp set switch, or the rotary mode switch, next in the most common problems list is the [b]start capacitor or the [b]hard start relay attached to its circuit...lastly...I would look for a burned wire on the [b]compressor terminal. These problems are what I see most often.
[b]NEVER, NEVER, NEVER... Look, or Troubleshoot A/C units with power connected unless you are qualified...looking at components is o.k. but
[b]ONLY with power disconnected from trailer.
Now one sneaky
problem with A/C is this...
If the trailer is run on too small a service cord the [b]compressor temp sensing switch will over heat tripping it open/ie. turn off compressor only...but... the fan will still run...
[b]this sensor built into the compressor motor will trip in 20 min or so of run time on too small/light gauge of a service cord, it requires hours for the compressor motor windings affecting the switch temps to cool down allowing it to reset.
(WARNING)
If the temp switch inside the compressor is
cycled too may times the
compressor motor will just not ever reset again... this failure of the temp switch means its new compressor time campers...Ouch!!!
Inadequate cord sizing is the #1 cause of compressor A/C failure. DO NOT BE CHEAP... GET THE RIGHT
[b]GAUGE OF CORD OF
[b]THE RIGHT LENGTH.
Make and model of the A/C unit may help me...Working with someone who has experience in
electrical trouble shooting procedures is a must. The process of trouble shooting is straight forward...Being able to read a volt ohm meter "V.O.M." is a non negotiable must have skill.
Some well written books are available.
Again, I find in most cases, A/C problems are commonly
electrical in nature and the fix inexpensive...Maybe in 50 units I work on do I actually do something in the refrigeration end of it.
I welcome any questions.
Harry
Quote:
I think the air conditioner in our new Bigfoot 21-ft might be defective or not big enough for the trailer. It is the factory installed unit. It will not cool the trailer although it runs and the air coming out feels cool. Example 82 outside, inside the trailer 80. Without the unit running, the temp. inside quickly climbs to 90+. Anyone else have problems with the factory installed air conditioners in their bigfoots?
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