2nd Gen Non-Engine/Transmission Help! Where's the local AC guru?

[OutbackDiesel]

What's wrong with my AC? It stopped working in December, I had it recharged and all was well. For about two months. Then, took it back in had it checked, the tech said that he thinks there is a leak in the evaporator. $1500. 00 to fix. No way can I drop 1500 on a fix for ac especially when it's just a guess. So, I let it go for about six weeks. I bought a recharge kit myself, when I hooked up the pressure gauge to the low side, with the temperature being about 70 degrees, each time the compressor clicked and engaged, the pressure would go up to 25 or thirty and then drop off when the compressor stopped. Which seems to me to mean that the system has a full charge, is not leaking, and likely has some other problem. Also the the line going into the firewall to the evaporator was pretty cold, the one coming back out of the firewall was much colder. So I think that part of the system is working well enough. Just no cold air. Also, not sure if it's worth mentioning, but the truck is now in a very humid climate, not sure if that has any bearing on the functionality of the system. Any help/advice would be very much appreciated.

 

[JKlopp]

Any AC tech worth going to should have found and repaired your leak prior to charging the system. If the leak was so small that he could not find it, he should have added a dye to the system that would visibly locate the leak in a few months. Todays electronic leak detectors will easily find a leak of only a few ounces of refrigerant a year. Your system holds several pounds of refrigerant. A leak that loses the charge in two months is a large leak and should have been very easy to find. If your technician was using soap bubbles or a flame type detector to find the leak, find another tech.



You indicated that you had charged the system yourself on the low side which is correct. But you also indicated that the pressure rose when the compressor was on. This is not correct. If you are on the low side (suction) the pressure will drop when the compressor is running. If you are on the high side (discharge) the pressure will rise when the compressor is on. If you are not POSITIVE you are connected to the low side you could be putting yourself in danger by overpressuring the refrigerant supply can.



My recommendation would be to find a tech that can properly diagnose your system.

 

[robertyoke]

If you want to diagnose it yourself then you will need a good set of gauges. you will need to know what is happening on the high side and you will need a thermometer. If you need to open up the system you will need a vacuum, and NO not a shop vac. don't just add freon or it will be overcharged and not work well.

-robert

 

[OutbackDiesel]

Thank you for your responses so far. The tech did charge the system in December with a dye and then looked for the leak in February with a UV light I think. He said he checked all over and could not determine where it was leaking from. Based on that, he said he felt almost positive that the evaporater was leaking. But like I said, I think the system is fully charged. Is there another component that could be responsible for the system not cooling the air assuming it is fully charged? When the pressure was rising, it was right after the click, however, I don't know if the click was the compressor engaging or disengaging. Since it was reading the right pressures (as near as I can tell in my inexperience), I assume that the system was charged as it should be... Was just wondering what the next thing to troubleshoot would be. There aren't many repair centers where I am now and quite possibly none that are qualified by today's standards to service the system or diagnose the problem correctly. . Thanks again for any further information. .

 

[MPalachuk]

You might start by pinching off one of the heater hoses and see if it makes a difference. Maybe there is something wrong with the doors that direct heat and it will override the system with the heat.

 

[Forrest Nearing]

these things are famous for getting leaks in the evap core...



$1500 is highway robery... I'd gladly do it for $700 w/ all Dodge parts!



Forrest

 

[woodsrat]

This is going to sound stupid but check it anyway. The fuse in the main box on the inner fender. My truck was doing the same thing thought the evap core was leaking so i ordered one after going without the air for a summer when i relized that the system was still charged went looking for another reason why no cold air. never thought to check the fuse because A/C worked just not cold. It had a blown fuse replaced it worked fine.

 

[Andy Redmond]

This is classic of the evap failing. The first several times it will pull a vacuum and hold a charge for a while then it will leak out every two days or so.



Run the a/c and use a jumper on the low psi switch for 15 sec. at the time for several times, then stick a leak detector wand up inside the blower box (remove the blower resistor). I bet it goes crazy!



Hey Forrest, have you priced the oem or aftermarket parts lately (evap core, heater core and accumalator dryer). Its close to $400 from Dodge and 8 hrs of hard labor. Plus Freon, oil etc. .



Good luck

Andy

 

[Forrest Nearing]

I've got a parts hookup at the Dodge house... I got my complete clutch hydraulics set for a little over what Peter could sell me just the master and slave cylinders... I can't remember what I paid for my evap core, but I want to say $150?



I've got a bunch of 134 left over from last summer (thank goodness)



I figure I'd probably walk away from the job w/ $400-500 cash in my pocket, and I could knock it out in less than 8hrs.



Forrest