Half of front vents blowing cold, other half blowing warm?

[shelzmike]

I just noticed this past week something strange in my 2000 Silhouette. In case you are unfamiliar, the vents in the front of the passenger area are situated with one to the left of the driver and one to the right of the passenger. In the center of the dash, there are three vents with the one in the middle being not adjustable.

So, I realized that the drivers side vents (the one all the way to the left - by the door - and the one on the right side of the driver (which is the left of the center group of vents) and the one directly in the middle) are blowing warm air - not hot, but like I have the temp turned to cold but do not have the AC button pushed. However, the passenger side vents are blowing very cold - noticeably so.

Now, here is the weirder thing, it is an off and on deal. Meaning, throughout a drive those vents blowing warm air will blow cold for a little while, then back to warm, etc. There does not seem to be any rhyme or reason to it.

Anyone know where to even start with this one?

Mike

[shelzmike]

No one? I still have this problem. I checked the refrigerant level and it is spot on and doesnt need to have any added. What should be my next step? This would be easier if they all were blowing warm air. What is throwing me off is the fact that it is only half the vents only some of the time.

Mike

[gmtech1]

Does this van have duel zone temp control?

[shelzmike]

No it does not. At least note between driver and passenger side. It does have dual zone as it pertains to front and back cabin areas.

Mike

[gmtech1]

How do you know the charge level is correct, from gauges? Or was the system recovered and recharged? A low charge will cause condition. The most accurate way to tell is to have the system recovered. The machine will weigh what has been removed (assuming it has been properly calibrated), and you'll know for sure.

[shelzmike]

Yeah, I plan on doing that anyway. My brother (who is HVAC cert) thinks the Orifice Tube might be clogged up as well based on some diagnostics over the phone. I somewhat agree, so I will have to get it recovered anyway.

Mike

[gmtech1]

Sounds like a good idea, please keep me posted on what you find. Thanks and good luck!

[Tech II]

If orifice tube was plugged, it would affect BOTH sides....agree with GMtech1....probably low on freon, if not dual zone....

[brcidd]

Sorry folks, no orifice tube on a 2000 U-van-- they use thermal expansion valves......

You have a low refrigerant charge-- refrogerant enters and boils off the passenger air flow fed side of evap first- then there is nothing left for the driver's side--- recover refrigerant- weigh it- know that you have less than half of required charge, then find and fix leak, and evac and recharge and be cool.....

[Oldsrip]

Hi all,

I am new here.

I reopened this because I have a similar problem, but with another symptom.
It sounds like I may have a vacuum leak behind the center dash vents. I can hear a hissing when I turn the blower fan on. I have never been in the dash of a silhouette.
This is my wife's and I don't drive it often, so I am unsure if the hissing is normal or part of my ac problem.

I also found that the radiator and condenser fans are both bad. So I am going to fix that before I get further into the ac problem.
Thanks in advance.

Joe W.

[LMP]

...please specify model year....

[Oldsrip]

Hi LMP,

It's a 2004 olds Silhouete van with ft and rear heat/ac.

Up date, I just installed a new condenser, radiator and cooling fans.
I haven't charged the a/c yet. I will do that in a day or 2' then I can get back on then ac vent problem.

Thanks,
Joe w.

[sbagdon]

Having the same problem with my 2000. Rear zone is great, right side of front is great, yet the left-of-three in the center blows defintely warmer (not hot, just not as cold) then the right-of-three. I've checked the high/cold with a gauge set, all appears ok, the best I could come up with was that the left side is pulling from the cabin, while the right side is passing through the evaporator. Anyone have ideas?

[shelzmike]

Since this was reopened, it reminded me I needed to come back and update on my result.

I purchased an orifice tube, but never got around to switching it out. We still had the problems, but then one day I noticed that the compressor was not kicking on anymore. I was actually somewhat happy because I thought maybe it had been the compressor the whole time that was the problem. I was gonna get it switched out, but didn't have the money so didn't for a long time.

A few months later, after much "coaxing" from my wife I broke down and decided that we would go look for another vehicle. We found a really nice used 06 Durango (which we love) and I was going to trade the van in, but it was in pretty bad shape AND it was boiling hot outside during the time we were looking, so I figured the AC not working might causes issues.

So, in sort of a "what the heck, I might as well try" moment, I decided to try refrigerant one more time (bc, I know that the compressor would stop working if the refrigerant was low). This time though, I bought one of the newer kind of can with the gauge on the top that actually had an ambient temp adjustment. I plugged it in and low and behold! It was completely empty according to the gauge! I put in 1 full and 1 half can and it still wasn't showing full yet so I thought maybe I had a leak somewhere, explaining the absence of refrigerant to begin with; however, this can claims leak sealing as well. Well, holding my breath, I started her up turned on the AC and I could not believe it! Not only was cold air blowing out of all the vents (and the compressor now working) that air was freaking COLD, so cold that I had to actually turn it off on the way to the dealership.

So there you have it...this was an initial case of low refrigerant and then a subsequent case of trying to use a crappy product - I was initially using a white can with a flimsy little blue gauge on it that was always saying full the entire time.

Thanks!

Mike

[brcidd]

Your refrigerant charge is low- checking with guage means zippo--also all air travels throught the evap irregardless of mode door or temp door setting..