I have this same problem on the same unit. It was low on R134a refrigerant. I found two common leak points on the interior evaporator, on is at the evaporator to copper lines and the other is the temp sensor clipped to the aluminum evaporator line. I found a hole in the line from the steel clip rubbing on the line. I removed the clip and sensor, put epoxy over the hole and placed the sensor into the epoxy as well, and let cure for 24 hours. Fixed after recharging.