There you have it. Anybody know what would cause this? The refrigerant is up to pressure, but I don't know what else to check. The front seems to be a little cooler when I turn off the rear ac. It's a 2001 Durango 5.9 SLT plus.
As always, any help is greatly appreciated. Sweating at stoplights just doesn't cut it for me.
Thanks, Gas.

 

Do you see a puddle right behind your right rear wheel whenever you have the a/c on? If so, then your rear a/c is getting refrigerant and the evap coil is working. Could be a fan issue. We'll leave it up o the a/c experts that will come online soon to help you.

 

I didn't know I should look there, but I will after work. I'm not sure if you're taking about the fan blowing air from the rear vents or possibly another one related to the rear ac that I don't know about. The vents in the rear blow air just fine, it's just that the air they blow is worse than useless.

 

The rear air has a blend air door that has an actuator motor on it. Usually in 80% of the time the rear air not blowing out cold is that the joint that the motor goes into for the blend air door will crack and this will cause it not to work at all. It usually will stay on the heat side and not move the door for the cold side to work. Dual A/C units take 2.44lbs of freon and that is the best way to tell if you have enough in your system. Recover, vacuum, and recharge with the correct amount of freon.

 

+1 Pete!

 

If, you have a roof mounted A/C unit on the rear. Then, you may have to change the expansion valve.

General A/C not getting cool:
1. Expansion valves may be plugged, overtime, they may become oversized and not cool properly. Think of a ball point pin with little tiny holes. That's your expansion valve.
2. The Dryer on a car is suppose to remove moisture in the A/C system. Over time this gets full. Water particles are in your line causing the expansion valve to prematurely freeze. Causing the A/C system not to function properly.

Expansion Valve & Dryer are cheap for the Durangos. I purchase mine from an A/C supplier shop locally here in Phoenix, Az. If, you go to the dealer, they are way more expensive. There were 2 o-rings I had to goto the dealer for because, the o-ring kit wasn't big enough. Expansion Valve around $25, Dryer was around $15, o-ring kit around $5

If, you have a compressor, you can goto harbor freight to get a vaccum pump for $12.99.
http://www.harborfreight.com/air-vac...ors-96677.html

Get you a set of gauges: $29
http://www.harborfreight.com/a-c-man...set-92649.html

Set your compressor to regulate at 90psi for the vaccum portion of the Job.

Once, your system is vaccummed. Charge the low side with the can turned upside down. Since it is liquid.

Your high side pressure should be 2X or 2.5X the outside temp.
Example. If your outside temps are 100deg, your highside pressure should be 200-250psi @ 2000 Engine RPM.

 

Wow, great info. I guess I know what I'm doing tomorrow. I should mention one other thing I noticed after work today. It doesn't seem that there is any difference between MAX ac and the non-recirculating setting in the front ac, and I also noticed that it seems to cool a little better at speed. I don't know if that will influence anyone's thinking, but I thought it would be worth mentioning now that I'm finally free to check my posts. I sure hope it doesn't suddenly get a lot more expensive. Also, I had forgotten (mainly because I just got used to it and it never seemed to matter) that the light on my mirror defroster button blinks continuously. The defroster still works, so I quit thinking about it. Now I'm wondering if it means my HVAC control module could be be involved in this. My front doesn't seem to recirculate and the rear doesn't blow cold air, and the lift always blinks. I wonder if I'll be looking for another control module, and if they are expensive. Well, either way, it looks like I've got the right group of guys to talk me through it.
Thanks for your help, and whatever further help you can provide.

 

When you turn your temp. ****, can you hear the plastic door open & close behind your dash? If, you can't it could be something wrong with you cable or the hinge inside of your HVAC box. My 2000 durango does not have an external valve that will shut off hot coolant from coming in the cab. This is all done inside the HVAC box. Meaning if the doors are bad, you could be getting hot air from the heater core. Thus, your car will not cool.

1st.: You really need to check your high side & low side pressure @ 2000 RPM
2nd: make sure the Efan is kicking on
3rd: chech your plastic HVAC doors by turning your temp **** & listen for movement behind your dash. This is the door that seperates the heater core & the cool side.


Then report back.

 

I went outside to check the blend box door. I moved my temp sliders and the temperature changed using both the driver and passenger sliders. At least I shouldn't have to tear apart the dash. I'll check at harbor freight after they open and see if they have the things I'll need in stock. Fortunately, I have a compressor, so I should be able to do what I need to do. How hard is it to change a dryer or expansion valve?

 

I finally got to check, and I do have a puddle by the back tire.