2004 Silverado A/C intermittent/not working

desertdoc

2004 Chevy Silverado 5.3L Z-71, 46,000 mi. automatic transmission. Approx. 2 months ago, the A/C became intermittent (very cold air when working), then progressively, the times it worked tapered off and now the A/C does not work, other than to blow hot air. The dual-zone electronic control seems to be working properly. The serpentine belt doesn't seem loose. The compressor pully is still turning (I had a Dodge that quit and froze up making an awful noise as the belt shreaded). I havn't had the system checked by a mechanic yet, but my father-in-law (Ford mechanic) doesn't think the system coolant is low because it was blowing very cold air when it worked, if only from time to time. Don't know if it has to do with the A/C issue, but sometimes the check engine light comes on. The engine is running fine, gears shift smoothly, the oil was recently changed, all fluids topped off, doesn't run hot, and I recently had a 20 point inspection done while the dealership replaced the gauge cluster (A/C must have been working then). No other issues found/reported then. I should add that the truck has set idle for long periods until this past spring due to my working off shore over the last 3 years (hence the 46K mileage). Hate to drop a small fortune on a minor/simple fix, if there is one. Is it likely the compressor, the coolant, clogged system (from sitting idle), the control unit, a relay, or ???

ndhulst

I have a 1999 silverado with same problem. it started progressively now the ac only works every once in awhile. and if its not working its blowing hot air. I did notice that if the ac was on it would turn off going over a bump or turn.(i didnt realize this till lately as it progressively got worse) i was just ready to change the heater core.. but if it something simpler im open to ideas. thanks

shamill

Does anyone know if there is a website that shows how to replace a blower motor resistor on a Chevy Silverado 2500 HD ?

headlight2004

Important !!! If your Heater has been steadily failing to "Heat"... Check your Anti Freeze Level.

obyone

www.alldatadiy.com

seamus1757

OK I understand that there were recalls on the instrument cluster(which I need to fix yet) but the oher problem is that the dual heat system is freaky it works passenger side but not driver side. one cold one hot, now I get no heat if IM sitting still but if I drive for like 5 mins (weather or not its warmed up) I get heat blowing and the blower works great and its not just blowingthru from driving . I get red hot air blowing but if i adjust it cooler? it kills the heat completely. Someone told Me it was certain sensors or servos's? that fail and won't switch heat /cool correctly HELPPPPPPPPPPPPP. IM not gonna go pay a dealer 600.00 to put a 15.00 servo in it

cliff85j

I purchased an 05 chevy silverado 1500 5.3L V8. I am very happy with truck. I had the oil changed 2000 miles ago and check it approximately every 500 miles. I checked it after 2000 miles and it was a quart low. the truck does not have a history of this problem. WHat would cause this to happen now, the truck only only has 55,000 miles on it? Would switching to synthetic oil make any difference

jjamontan

I also have a 1999 silverado and it is now stuck on heat. I know that the air is working just fine. last year the vent was stuck on the defrost then after time it went back to the dash vents. Now it got stuck on heat even when it is on the cool setting. Does this sound like the issue you were having? And did you get it fixed, what was the problem?

joeyb71

I have that problem. did you ever find out what the problem was?

kim_j

Did you get an answer? Having the same problem with my 2005 Silverado.

gmcustsvc

kim_j,
I apologize you are experiencing concerns with your vehicle. Have you spoke with your dealer?
Christina
GM Customer Service

zula49

Did you get a reply to this, my 2000 pickup is doing the same thing.

tbear921

I have a 2004 Chevy Silverado that does the same thing. I have the dual temperature setting and alot of people are having the same problem. I have read on the National Hwy Safety Commission that there are a lot of complaints for the same thing. Its the actuator, but I don't know how to fix it. When I turn on AC, both sides will blow cold for a few minutes and if I hit a small bump in the road, the driver's side will turn to extremely hot heat and I have to turn off the engine to reset it and it goes back to cold air until I hit another bump in the road. If I am using the heater, it does the opposite, the air goes from hot to ice cold like the AC is on but only on the driver's side. The actuator is inside the vehicle up above the gas pedal in a plastic housing with three screws.

sla130

Just blew 129.00 on a new control panel for the heat/ac control dual zone on my 2005 Silverado. (nope can't send it back cuz I demolished the old one to see what made it tick, er not tick) Driver side stays cold, while passenger side works fine. During the summer the air went hot ( only once)while the a/c was working and the blower motor quit working, GM had a recall on the blower motor so thats fine.....just can't get any heat out of the drivers side. Any idea's?

Buck_the_handyMann69

The driverside blowing hot while the passenger side blows cold is a blower door actuator. A simple fix is to add a shut off valve in both of the heater core hoses so the hot coolant cant flow to the heater core unless the valves are opened.

thecardoc3

Buck_the_handyMann69 said:

The driverside blowing hot while the passenger side blows cold is a blower door actuator. A simple fix is to add a shut off valve in both of the heater core hoses so the hot coolant cant flow to the heater core unless the valves are opened.

Does the engine have a coolant bypass circuit other than the heater core? If not then that would be a bad idea.