2005 AC Help - What am I doing wrong?

[ElecTape]

Ok 2005 3.7L. Bought used a couple of years ago. AC didn't work and I could smell coolant in the truck. Replaced everything on AC system (All parts new) and heater core. Evacuated and recharged AC system worked fantastic. Within a couple of months, AC stopped getting cold. Attached gauges and found low on freon R134-a. Added some and thought nothing of it. Again, a couple of months go by same issue. Hmm, kind of looked like maybe the Shrader valve for the low side was leaking. Swapped out the valve vacuumed and recharged, everything was good. Well, low an behold a year goes by summer hits no ac. Ugh, decide to replace the low line, vacuum, and recharge. Here we are now about a year from the last time no ac again.

So I decided ok, I'm not going to try and Band-Aid it again. I'll order a New Compressor, Dryer, Condenser core, and new hoses (Low side (liquid line with orifice tube), High side (Discharge to condenser), and Suction (Evaporator to Compressor). I did not replace the all-metal L-shaped hose from Dryer to Evaporator, and the Evaporator. I also did not replace the 2 sensors either.

Ok so here's what I did.
1- Used AC flush on the Evaporator and metal L-shaped hose.
2- Installed New Compressor and belt.
3- Installed new condenser core.
4- Installed new Liquid line.
5- Installed new Discharge line.
6- Reused old sensors.
7- Tried to install the new Suction line. The wrong line was sent. Ugh.
8- Flushed old Suction line and reinstalled.
9- Sucked in 4 oz PAG 46 oil with dye.
10- Pulled vacuum on the system for 1hr or so.
11- Checked for any vacuum leaks for about 1/2 hour and ran to store for additional freon.

So here is where things went strange for me.

1 - Started jeep and set the blower to 4, recycle air, coldest setting, and AC button on.
2 - Attached CAN tap and a new can of freon, opened the valve to bleed the air from the freon line to the gauges.
3 - Opened the system to the Freon can, and nothing... Hmm ok, that's odd. Usually, after a second or two the system kicks on due to the freon going into the system. This did not happen.

So, I pulled the sensor plug on the dryer and jumped the wires to kick the compressor on. It seems to be taking freon now, but slow. I get two cans in after quite some time and the AC is cold at the vents everything seems fine.

Today I was swapping out the new fog lights on the front and started the jeep, to check functionality on the lights and turned the AC on to just double check it. Lights check out, but no cold air after running for a few minutes. I notice the AC system is cycling on for a few then off for a few, so I go get my gauges thinking maybe it's just low since it didn't seem to setup right. When connected the High side seems to be a bit high climbing to 300, and the low side is high going to about 70. Now it's 80 outside so if my memory serves me right, I'm looking for about 40-50psi on the low and like 150-210 on the high?

The liquid line is cold and sweaty, and the discharge to the condenser is hot.

I let a little freon out since that seems high. Now I get 40 psi on the low side. Now the liquid line seems to be forming ice on the bottom of the line. However still now cold air in the truck. I turned the system off for a bit just encase I froze up something, then I took it for a drive around the neighborhood. Well, it's not cooling whatsoever.

Any ideas?

A - Is it possible one of my pressure sensors is bad?
B - Does the Suction line (Dryer to Compressor) have something in it like the orifice tube that could be bad?
C - Does this sound like I could have possibly swapped the lines on the dryer? Not sure that's even possible.

Any help would really be appreciated, as this is the little woman's ride. Got to make her happy.

 

[Ksat]

First off, a/c flushing should, at most, only be performed on the evaporator and refrigerant lines that are free-flowing/not have anything like mufflers, filters, orifice tubes, etc. on them. Both should be removed from the vehicle when flushing to ensure the solvents are fully drained. Blowing compressed air through either while they're are still semi-installed on the vehicle with the hope you get all of it out is a big no no.

With that off my chest, When you first started charging the system, did the pressure on the low side increase prior to you jumping the low side pressure switch? If so, what did it rise to? Also, what position did you have the can in (inverted, right side up)?

A generic pressure chart I use for 134 says low side should be 40-50psi and high side should be 175-210psi @ 80 degrees F ambient, so your current readings look in the ballpark.

Do you still have the connector on the low pressure switch jumpered? If so, that's not a good idea as the compressor can get damaged if pressure were to drop too low. As for the high side switch, if you see the compressor kick off when the pressure on your high side gauge reaches a certain max threshold, that pretty much indicates it's working, at least to some degree.

If the inlet to the evaporator feels cold, but you're not getting that transferred to the cabin, your problem could be blend door-related. A frozen evap could also cause that, but you would initially get some a/c rolling in there if the car had been sitting a few hours prior.

You may want to change the HVAC switch from re-circ to another setting with blower on high to listen for a change in blower tone, just to make sure the door is opening and closing as it's supposed to.

 

[ElecTape]

@Ksat - I only flushed the Evaporator, The short all metal line from the Evaporator to the Dryer IN port, and the Suction line (Line from Dryer out to Compressor.) Everything else was brand new installed.


Well, I was able to spend a little time with it this morning to try and see if I could get it going.

The first thing I looked at was the Blend door motor under the passenger airbag. Well, I can see the actuator turning the shaft when operating the temperature control. I also checked the recirculation flap, and it opens and closes correctly. I Examined the driver's vacuum actuator on the driver's side for the vent output, and it also works correctly when turning the position knob.

Of course, this doesn't rule out if the blend door is broken inside of the air box.

Attaching the gauges with the AC off, they both seemed to convey about the same pressure. When I turned on the AC the pressure slowly increased from 10 on the low side up to 90 psi and the high side cycled about 150-200ish.

So that would seem to me to suggest that I might have the hoses routed incorrectly, like maybe the in and out of the compressor, or a blockage.

Looking at the compressor there are 2 ports, one above the other. In the top port, I have the high-side hose. It's going to the condenser port on the driver's side. The passenger side of the condenser is the low-side hose going to the firewall, where the evaporator ports are. It is connected to the driver's side port. On the passenger side of the evaporator, I have the little metal hose going into the IN, port center on the dryer. Then the outer port on the dryer is the Suction line going back to the compressor on the lower port.

I am hoping someone can verify if this is the correct routing.

Question - Does the Suction line have any valve in it? It didn't seem to have any restrictions when I flushed it.

Question - Could it be a bad Dryer or maybe too much oil in the system?

At this point, I think I will pull the Dryer, and compressor, and run a can of flush thru all the hoses, condenser, and evaporator. Drain the compressor, install a new Dryer, add new pag oil, and vacuum the system to try and recharge again.

Question - should I add the pag oil before or after the vacuum?

 

[ElecTape]

Or, do you think I could just get by with vacuuming the system and a recharge?

 

[blackhawk]

If you have high pressure on high side the condenser must be retaining pressure. The dryer was not change, right?

 

[ElecTape]

If you have high pressure on high side the condenser must be retaining pressure. The dryer was not change, right?

The dryer was replaced.

 

[blackhawk]

The dryer comes with a plastic inside each orifice that most be removed before installing. Just be sure you took them off

 

[ElecTape]

The dryer comes with a plastic inside each orifice that most be removed before installing. Just be sure you took them off

? The plugs sealing the ports? Yes, these were removed. Not sure what you're talking about.