Full Time A/C

[Lone Eagle]

This is a two part story that some of you might be interested in. Part 1 was a couple months ago when I posted a question about my A/C pump running in all the vent modes. A couple guys came back and said this was normal for this truck. I went along with the gag and blew it off as being right. I have since changed my mind. Part 2 of this story is that the A/C runs all the time now that the weather is warming up. The compressor is working and making 36 to 38 degree air in both vent modes. The A/c light does not come on. I switched it to the A/C position, the light comes on but nothing changes. The outside temp was 68 degrees. I don't know how many horses it takes to run this compressor but it is not free and surely will wear out sooner. There is bound to be a little mileage to be gained here. I am going to visit the dealer tomorrow. I would be interested to know if all are like this. Later! Lone Eagle

[AzKevin]

I also noticed some strange A/C behavior. When the recirculation mode is selected, the A/C is always enabled. This can be an odd mode when it's chilly outdoors.

[ 04-08-2002: Message edited by: AzKevin ]</p>

[MaxACL]

The older Chevys ('66) would run the AC when the defroster was selected.....?

[SoCalDMAX]

Sounds like Lone Eagle's computer that controls the A/C (no idea the correct name) is wacked out. Like my Dept. Head at work, "We run the A/C in the winter and heater in the summer, it's cheaper that way, it never comes on..."

Hi Kevin,

Lemme guess, the owner's manual wasn't technical enough for you, so you just skimmed thru it, huh? ;) :D :D

IIRC, when in recirc mode, the A/C is on low, if you want to turn it off, select fresh air (and go back to recirc if you want.) The A/C should stay off until the next startup. If you want A/C on low, select recirc., turn A/C on, then off.

Or is this an AZ option? CA models get catalytic convertors and AZ models get full time A/C?

While I've got your attention, did a brown truck drop off any interesting boxes yet? Did you kiss him/her and destroy the box opening it up? Is your wife getting suspicious why you're interested in driving to the store for ice cream at 2AM? Do you need new tires yet?

Regards, Steve

[NutNbutGMC]

HVAC = conditioned air =&gt; air conditioner. It will activate to do the job, as long as conditioned air is in request. L.E., may be that your controller gizmo is on the frits, but the AC will engage when you tell it what ya' need in the way of conditioned air, under proper operating conditions. Don't forget the temperature controller, to change the air temperature for those "odd be an odd mode" days. I have a window unit mounted in my rear window slide opening, for those kind of days. :D :D

[Lone Eagle]

Thanks SoCalDMAX but no cigar. Air is on all the time in the recirculation mode and it ain't on low cool. Any more ideas? The book doesn't explain this. Later! Lone Eagle

[wizkid]

My A/C was doing that. After having the batteries frozen 4 times, and after having pointed the bad relay out to the dealer (on my second visit) :( they finally replaced my AC relay.

Check and see if it's disconnecting after you shut the engine off and take out the keys. GM isn't putting mil spec relays in these trucks by a long-shot! I finally got my relay replaced on the fifth visit. The batteries being frozen 4 times I'm sure has sucked the life out of them. The dealer wouldn't replace them, because they would still start the truck.

[AzKevin]

Steve,

It's one of those hunter/gatherer things. We'd rather flail/toil than look at an owners manual. :D

Then again I can't recall ever driving a car/truck that had quite the same recirculation sequence. Spose an Arizonan should be the last one complaining about A/C working. ;)

NutNButGMC,

I hear you what your not saying! :D

[Mic]

Lone Eagle: Might want to check this out in the manual:

Page 3-4 of silverado supplement:

BLEND: Airflow is delivered through the heater
floor outlets, center floor console outlets (if equipped),
the windshield defroster outlets and the side window
defroster outlets. The air flow can be divided between
HEATER and DEFROST depending upon where
the knob is placed between the settings. The air
conditioning compressor may run to dehumidify the
air to prevent window fogging.


Basically, with any defrost (blended or not) the A/C compressor will run.

[Allison Jettester]

Lone Eagle,
I have an 02 GMC EC LB D/A and my A/C will not come on at any time if I push the A/C button off. If the A/C light is on, and I push the A/C button, the light goes off and the A/C disengages and stays disengaged, even on defrost. If yours does otherwise, I would check with the dealer.

Joe

[Lone Eagle]

I went in and talked with my local Chev service manager. He didn't know how the system was suppose to work. The only bullitin we could fine was for intermittent mode problems. We called the GM Tech rep. He said there was a bullitin out that said this was normal operation but he could not give us the number. I checked a new truck just like mine on the lot and it worked exactly the same way. I know why the compressor runs in the defrost modes. It is recirculating air through the hot hot evaporator coil to dehumidify it. I also know that HVAC stands for heating, ventilation and air conditioning. I talked to a couple of the the HVAC mechanics that I supervise at work before I posted. They said this is the only system they have seen that operates like this. Mine goes right to recirculate when I sellect one of the vent modes. I will just have to remember to sellect outside air. Thanks for all the replies. Later! Lone Eagle :D

[ 04-09-2002: Message edited by: Lone Eagle ]</p>

[DaveRuane]

Didn't read all the posts carefully but the answer is:

In RECIRCULATING MODE, AC is on and running - no if, ands or buts about it.

[DmaxMaverick]

Oops!

Couldn't find the "delete" button.

[ 04-27-2002: Message edited by: DmaxMaverick ]</p>