rear air not cooling?

1996 T&C LXi, 150K miles, recent evacution and recharge, front air works very well.

BUT....when I turn on the rear air it doesn't cool as far as I can tell, and it gradually causes the front air to get warmer. I did have to fiddle with the blend door controller last year (bought a replacement that I have not installed), but I don't think the front blend door is what is causing the air to warm when the rear is turned on.

Is something clogged?

First off, turn the a/c on. Front only. Let it get nice and cold. Then turn on the REAR a/c. Crawl under the rear of the vehicle, and look for the a/c lines. If the REAR a/c is working properly, then 1 line will be cold to the touch. You'll have hoses running to the rear heater core, so if everything is working properly, you should have 3 lines hot to the touch, and 1 cool/cold to the touch.

This is to make sure the rear a/c is actually working.

If the a/c line stays cool/cold, but your only feeling warm air coming out the REAR vents, then you have a BLEND DOOR ACTUATOR problem.

If the a/c line begins to warm up, then you have a flow problem....most likely an expansion valve has gone bad. They're not too hard to fix, but then again, i've been doing a/c repair for 17 years.

Let me know what you find. I'll walk you through the next steps.

Thank you. I'l give it a try asap.

Now, when you say a "blend door" problem, do you mean my front blend door? I do think I have a problem up there because sometimes I have to slide the two controllers over to "hot" and back a few times for the air to really get cold. I never put it in because it seemed to be working ok the last few times....until I used the rear.

So, maybe that's a good starter anyway? But, is there also a rear blend door?

Yes, there is a rear blend door.

Let me ask you, do you have a dual climate system up front? Meaning, you can have cold air one the drivers side, and the passenger can have warm air on their side.

If you do, then I would strongly suggest you have your a/c system properly evacuated and recharged. I can't tell you how many times people have problems simply because they do not have proper a/c charge. I have my own a/c machine with a very accurate scale....it can even detect the weight of a quarter. Under-charge and over-charge are some of the biggest problems non-professionals cause them selves. Being a DIY can save you money, but it can also cost you.

But back to your problem. If your front blend door is acting up, then your ac may be working great, just the blend door "walking" or to the hot side. In either case, you would have to replace the blend door actuator....and that's something a DIY might not have the knowledge to do.

Do the checks I asked you to do....report back to me what you find.

Thanks.

Yes, there is a rear blend door.

Let me ask you, do you have a dual climate system up front? Meaning, you can have cold air one the drivers side, and the passenger can have warm air on their side.

If you do, then I would strongly suggest you have your a/c system properly evacuated and recharged. I can't tell you how many times people have problems simply because they do not have proper a/c charge. I have my own a/c machine with a very accurate scale....it can even detect the weight of a quarter. Under-charge and over-charge are some of the biggest problems non-professionals cause them selves. Being a DIY can save you money, but it can also cost you.

But back to your problem. If your front blend door is acting up, then your ac may be working great, just the blend door "walking" or to the hot side. In either case, you would have to replace the blend door actuator....and that's something a DIY might not have the knowledge to do.

Do the checks I asked you to do....report back to me what you find.

Thanks.

Yes, it has the dual front controls. System was evacuated and recharged last year, but the front blend door issue has been happening for quite a few months, and the rear air issue didn't seem to get a lot better.

That front blend door does seem to do just what you said....start cold, then move to warm by itself. The replacement unit I have has everything in place on the panel section. I should be able to R&R by plug-in I think.

I'll go through the rear tests as soon as I can.

Thanks.