Another A/C Question

[DoubleBadger]

Long time lurker, first time poster—this is a GREAT site. Anyway, I’ve got a 2000 Eldorado that I’ve been having problems with the A/C. The problem, which probably occurs about 85% of the time, is that when I hit the “Temp/Auto” knob to turn the system on automatic climate control, I start getting hot air out of the vents. REALLY hot air out of the vents (or maybe it’s just the fact that I just moved to AZ so it feels hotter than it is). In any event, when it does this, the air coming out of the vents is nowhere near the temperature I've "dailed" up. Other times, however, the system works fine and I get nice cool air out that feels about equal to the temperature I’ve “dialed” up on the automatic climate control.

I’ve had the car almost 2 years and the climate control system worked fine when I got it. I haven’t seen any messages on the DIC saying “Low Refrigerant” so I assume that’s not the problem. Since it’s going to get warm here in a couple of days and I want to have an A/C that works all the time, I pulled the codes and the following came up:

IPC U1301 history (“Class 2 short to battery”) and

RFA U1000 history (“Class 2 communication malfunction”)

Since I’m a total novice on car repair, I guess I’m wondering if anyone else has had this problem or can take a guess at what it might be and how much it might cost. It doesn’t seem to me that these codes really relate to the A/C, but I don’t know.

Any thoughts, suggestions, or advice is GREATLY appreciated!

Thanks for your help!

Mark

[Ranger]

Mark,

Can't tell you much about the codes except that they are "historical" NOT current so they probably are not causing your problem. Clear them and see if they return. Maybe they were set by pulling the battery power at some point. Done that lately?

On a related subject I frequently have cool air comming from the left side vents and warm air comming from the right side vents. I can't find a problem but the cure is simply to run the temp up to 90 and back down to 70 or whatever. From that point on it seems to work flawlessly.