2003 Dodge Grand Caravan-AC Blows warm Air

[georgeciccarone]

Any ideas what to check before I head to the $hop?

Please explain like I'm 5 years old, ok? :)

I checked the fuse under the dash but cant tell if its bad or not. Are there more fuses to check, and if so where? Any other thoughts ideas?


Much thanks All.

[XDGT03]

George,

It is going to cost you some money to find out what the problem is. I could be about 10 different things. Most likely you have a leak. That is going to cost you between $400 and $1000 to have s shop repair it. You can save a considerable amount of money if you can do DIY.

[rotis]

Mine was warm and I had it charged for $20

[Rick99]

Mine was warm and I had it charged for $20

That's the exception rather than the rule, and it is OK if you have a very slow leak. If the leak is too large to get away with this, as it usually is, it will have to be repaired.

George-- $35 spent on an a/c manifold gauge set from Harborfreight.com would be an excellent investment if you have the will to do this yourself.

In an A/C system you have a several possible problems--

Electrical-- evaporator temperature sensor, pressure sensor(s), a/c request signal from cabin, a/c on signal from PCM, the a/c clutch itself (an electromagnet that engages the A/C clutch to turn on the compressor.)

Mechanical-- leaks in various components, bad compressor, worn clutch. You could fail to get cool air because of a failure of the "blend door" that controls airflow over the A/C evaporator that cools the air in the cabin.

By far the most common problem is a low charge of refrigerant caused by a leak in the system (A/C systems do not "use up" refrigerant).

So before spinning wheels with a lot of other possibilities, here are the quick checks I'd do if it were my van:

1) touch the output pipe from the evaporator at the firewall to see if it is cool-- if it is cooling down maybe there's a blend door problem.

2) observe the compressor clutch with the A/C turned on. (The center part of the pully will spin when it is engaged and it will make a click every time it engages and disengages.) Check to see if it is coming on at all, and if so how long does it stay on before it cycles off again-- if it is coming on at all, you can rule out everything electrical other than the sensors.

3) Check the pressures with the manifold gauge set (not a cheapo gauge that comes with a refill kit) you will need both high-side and low-side readings. Although these will not directly tell you if you have a proper charge, they will tell you if you have a very low charge (as the low-side pressure comes up to about 45, the clutch engages and quickly draws it down to 30 and turns off then repeats this cycle in rapid succession.

Resist the temptation to just throw some more refrigerant in there. The refill kits make you think it's like filling a tire (just get it in the green zone on the gauge), but it's far different. If you overcharge, you risk destroying your compressor which will cost you a lot more.

[rotis]

@rick - it may be the exception but it has been my experience that cars need to have their ac charged every couple years. I have a 2003 caravan and they have a pretty small system. If it is a little low then you don't get cold air.

But for disclosure sake, my ac was not completely warm, it just did not really get cold anymore.

Most ac shops will do a pressure test for free. That should give you a pretty good indication where you are at.

[TomQuick]

As rick said, A/C systems don't "use" refrigerant. If it is low, there is a leak, it is that simple. It may be a very slow leak, and you may be able to get away with recharging the system every year or two, but if it is low there is a leak, and the proper way to deal with it is to find the leak and repair it, then recharge the system.