QuestionHello,
I have a 99 Ford E350 with a motorcoach conversion. The AC has been charged vacumed and the compressor has been changed. Nothing seems to work on making cold air blow. The is good pressure coming out just not cold. Checked for leaks and doesn't seem to be any. Out of options please help.
AnswerPryor,
I am sure I can help you with this problem but it may take multiple correspondence and some patience to diagnose it correctly.
Lets start at the beginning:
1. AC system has correct amount of proper refrigerant. Conversion vans may have more refrigeration requirements with additional lines and components.
2. AC system has correct amount of proper refrigerant? I can't stress this enough, too low or too high and adjust as necessary.
3. AC on High, compressor is running? If not that is a different trouble tree entirely I can help you with.
4. Install gauges and what are dynamic pressures?
5. Have no gauges? May be difficult to accurately diagnose but we can narrow it down:
Take a look at the compressor and there will be two AC lines going to it. One will be smaller in diameter and that we will call the liquid high side line. CARFULLY touch is with your hand. I mean CAREFULLY at first. If there is a restriction in the condenser or before the condenser the temperature of that line can burn you.
That line should be fairly warm to the touch as compressing a gas causes the pressure and temperature to go up. It then gets sent to the condenser to turn it in to a lower pressure liquid by irradiating the heat through all the fins at the front of the vehicle where air flow is best. If you can place your hand on the condenser (rad in very front) it shoudl have a uniform temperature with no hot or cold spots indicating restrictions or bypasses. One well places rock off the road can make for some funny temperature readings and it happens.
Now follow the line off the condenser that goes to your front evaporator. Place your hand on it carefully and it should be luke warm to the touch. Make sure you grab it near the condenser and keep touching it all the way to the evaporator. There should be a point where the line changes temperature.
The reason I am starting you in this direction is because you said you replaced the Compressor. If the compressor had a catastrophic failure such as bearing disintegration that particulate matter has to go somewhere and it usually ends up in the condenser or the fixed orifice tube. Ford in those years uses an orifice tube as part of the liquid line that goes to the evaporator and it may be plugged with debris. If you have AC gauges it would be very helpful to tell me the dynamic pressures at idle.
I hope this was helpful and I look forward to hearing inspection results.
Wayne
