98 Dodge 2500 A/C problem
#1
08-31-06, 07:11 PM
98 Dodge 2500 A/C problem
This pickup has 90k miles with an a/c unit that worked fine until this past week. I purchased this vehicle new and the a/c has never required service, so there has been no products entered into the system.
The problem is that there is no cooling air. As the unit failed over a two or three day period, it began to blow less and less cold air. I thought it likely needing refrigerant, until I did a little troubleshooting. I found that the compressor is running, and the line out is hot as expected and the line in is very cold. From this observation, the compressor is doing its job, so where else can I look in troubleshooting this problem?
The problem is that there is no cooling air. As the unit failed over a two or three day period, it began to blow less and less cold air. I thought it likely needing refrigerant, until I did a little troubleshooting. I found that the compressor is running, and the line out is hot as expected and the line in is very cold. From this observation, the compressor is doing its job, so where else can I look in troubleshooting this problem?
#2
10-01-06, 09:14 AM
Solved
I'll try to make the update brief.
Compressor was short cycling, on 8 seconds, off 3 seconds, continuously.
The system has two pressure switches to help protect the system. One is high pressure, near the compressor, the other low pressure, on the accumulator near the firewall and evaporator. The "low-side" switch is $36 dollars from Dodge, I now have a "good" spare, sometimes the cost of D-I-Y work.
The compressor was short cycling because as it ran, the refrigerant on the "low" side would starve, and pressure would drop too much, shutting the system down. Then, as the pressure equalizes from the "high" side, the switch would see sufficient pressure and turn the compressor back on.
The solution is two parts. With A/C gauges attached, I added R134a refrigerant. Second, there has to be a LEAK someplace, so now, if the leak isn't EXTREMELY slow, I will add refrigerant with the UV dye, and try to find the leak and make the repair.
Compressor was short cycling, on 8 seconds, off 3 seconds, continuously.
The system has two pressure switches to help protect the system. One is high pressure, near the compressor, the other low pressure, on the accumulator near the firewall and evaporator. The "low-side" switch is $36 dollars from Dodge, I now have a "good" spare, sometimes the cost of D-I-Y work.
The compressor was short cycling because as it ran, the refrigerant on the "low" side would starve, and pressure would drop too much, shutting the system down. Then, as the pressure equalizes from the "high" side, the switch would see sufficient pressure and turn the compressor back on.
The solution is two parts. With A/C gauges attached, I added R134a refrigerant. Second, there has to be a LEAK someplace, so now, if the leak isn't EXTREMELY slow, I will add refrigerant with the UV dye, and try to find the leak and make the repair.
#3
10-04-06, 02:13 PM
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Also, many vehicle manufacturers made the A/C condenser out of steel which corrodes pretty fast. This is what happened to my 96 Ranger. The corroding condenser leaked out my refrigerant. Check that out as well. It's the round orifice tube usually near the firewall or near the evaporator.
