Here are the options :
1. Check your filter. If it is dirty and clogged, it might be freezing the compressor and also stopping the cold air to flow smoothly to the outlets. As a result, you may not feel cool air from your outlet. Changing the filter will solve your problem.
2. The freon gas may not be sufficient in the compressor to cool the air. This may happen if your unit is many years old, or there is some leakage in your house of the cold air. Contact a professional to fill up the right type of freon gas. There should be temperature difference of 20 degrees Fahrenheit, if there is sufficient freon in the compressor.
An air conditioner blows out heat
Portable air conditioner will not blow cold air. What to do?
If it does blow just not cold air you should see if it needs to be recharged
diagram for 1999 chev subarban air conditioner
you would need to add freon
gas leak or wrong wiring
You have to get it recharged. you have no freeon left which makes the cold air
You are low on coolant to the heater core.
Coming out of the vents around 43 degrees
i have a pioneer travel trailer, air conditioner the compressor does not come on please advise is there internal switch?
Because that's the way there made to blow hot airbecause it's not like a heater and it's not like something that makes it cold it blows any kind of air .
There are several causes that an air conditioner is only blowing cold air for a short period of time then only blow hot air and then not going back to cold. This is especially common in the hotter weather including in the 90s and above. It could be from the air conditioner freezing over. You can fix this by simple trouble shooting and if that doesn't work call a repair man.