90zxdriver Posted July 15, 2010 Report Share Posted July 15, 2010 OK guys so I have had this occur a handfull of times (maybe 6 or so) since I got the truck. Sometimes my A/C just blows hot air if the truck is sitting in park. It seems to only do it when I first start the truck. If I drive it then park it the problem isn't there. For example, today I went to go sit in my truck and eat lunch in the nice cold A/C. I get in there, start it up and crank the air and it just blows warm air, yes, I gave it more than enough time to cool down. Its like the compressor wasn't kicked on at all. Now here is the funny part, if I move the truck the A/C kicks right on and blows ice cold. So, when it did this today I put it in drive, pulled forward about 10 ft and then backed back up to where I was and the A/C worked great and continued to until I finished lunch. It has never given me any problems while the truck is in motion. Has anybody else had their truck play these kind of games with them too? I don't think there is really anything wrong because other than the few times it has done this it always blows ice cold. Its weird thoughts? Quote Link to comment Share on other sites More sharing options...
tonycillo Posted July 15, 2010 Report Share Posted July 15, 2010 i some what have the same prob..... mine kicks the ac on and off if the truck sits in the sun. like i get off work and the ac kicks on and off for like the frist 5 minutes then its all good from there...... am i just low on free-on Quote Link to comment Share on other sites More sharing options...
Carl Eagle Posted July 15, 2010 Report Share Posted July 15, 2010 I think you may have a low charge. Quote Link to comment Share on other sites More sharing options...
wody Posted July 15, 2010 Report Share Posted July 15, 2010 it sounds like 90zx is over charged and red04 has a low charge. a quick cycle like you, red04, is normal for a low charge. on the other hand, 90zx's situation is a bit different. i'd have to see the pressures, but i am willing to bet that the pressure in the discharge line is a bit high after sitting in the sun for a while, but once air starts moving over the condenser and dropping the discharge pressure the a/c will kick on. since 03-04's have a viscous fan instead of e-fans, the a/c system has less control over the fans, and while sitting at idle the viscous fan will only pull what air it can. while e-fans can pull more when needed by running both fans. next time just try raising the rpms to about 1500-2000 to see if the a/c kicks on instead of moving the truck. after running the a/c and then turning the truck off, can you hear the a/c pressures equalize? it sounds like an air leak. i'm looking forward to hearing back on some of these suggestions and questions...we'll get this figured out! Quote Link to comment Share on other sites More sharing options...
cadillacbob Posted July 17, 2010 Report Share Posted July 17, 2010 [ probably needs a a/c cut out switch that mounts near the firewall... common issue on our trucks,,,do a search... Quote Link to comment Share on other sites More sharing options...
wody Posted July 18, 2010 Report Share Posted July 18, 2010 [ probably needs a a/c cut out switch that mounts near the firewall... common issue on our trucks,,,do a search... need to verify the charge level first. Quote Link to comment Share on other sites More sharing options...
tawss04 Posted July 18, 2010 Report Share Posted July 18, 2010 I agree you need to see how much 134a is in the system, these 134a syste mare real touchy on how much freon is in the system. The old R12 system are much more giving. The low pressure cycling switch is a big problem for GM. There are also a few other issues with these trucks, the C4, C5 and C8 A/C connectors on the right side of the dash coem loose. The A/C harness that runs down behind the glovebox near the center console rubbs thru the dash support and the Acuators door motors go bad. My A/C shop bolwing hot air on the drivers side at times and ice cold on the pass side. Still working on it, narrowing it down to possibly being the drivers blend door. Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted July 18, 2010 Author Report Share Posted July 18, 2010 Next time the truck does this I'll try kicking up the rmp's and see if that helps. This could be my excuse for efans! I'll also get the charge checked next time its in the shop. I just had it at Chevy today to have the tranny and coolant fluids flushed/changed and my dumb a$$ didn't even think to have them check the a/c charge.... DUH! Its going back in a couple weeks to have the power steering and fuel system cleaned and fuel filter changed... I'll get it checked then. This preventative maintenance crap adds up quick! Prob gonna be about 5-6 hundred to get all my fluids flushed and replaced! h well though, at least I don't have to have a 'tune-up' until 100k. Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted July 31, 2010 Author Report Share Posted July 31, 2010 alright, so the a/c did the warm air thing for about 30 seconds today after I ran into a store (it was hot today too!). Came out after 15 mins or so and started driving home. A/C was blowing warm then I herd a hissing sound coming from behind the dash/firewall area and the A/C started to blow cold and by the time the hissing stopped, it was blowing ice cold as usual. I've also noticed this hissing sound after I shut the truck off. Quote Link to comment Share on other sites More sharing options...
wody Posted July 31, 2010 Report Share Posted July 31, 2010 whenever you get a chance, verify charge. Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted July 31, 2010 Author Report Share Posted July 31, 2010 I've got to get alignment so I'll get it checked out then Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted August 7, 2010 Author Report Share Posted August 7, 2010 Finally got the truck aligned today and it rides like new again! They checked the A/C pressure while it was there and said the pressure is exactly where it should be. They didn't tell me what it was and were closing as I was picking it up so I forgot to get a exact pressure reading but its where it should be. Of course the A/c was perfect for them. Anyway they are saying I could throw a new pressure switch in there and see what that does but I hate to play part darts. Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted August 21, 2010 Author Report Share Posted August 21, 2010 The truck has been so good lately but today it decided to play games again. 95 degrees out and I had the cab full of passengers (for the first time) and of course as I'm talking the truck up it is blowing hot air. We were down town where there were a lot of lights so it would blow hot when I was stopped at a light and then blow cold when I drove from red light to red light. After about the third light I put it in neutral and revv'd it to get the fan to pull air which usually will kick the a/c back on. Not this time though, not only did the a/c not kick back on but the truck actually started to get hot! I watched the gauge climb to a little over 3/4. Once I stopped revving it the temp went back down to normal (middle of the gauge). Once we got out of the lights and were moving the a/c worked flawlessly. I even sat in a parking lot for about 20 mins with the a/c on full blast and it never blew hot and the truck never started to overheat. So, if it needs a pressure switch, fine but I really hate to replace things that *might* fix the problem. I'm also wondering if a set of e-fans will solve the problem or are there underlying issues with the a/c? Any idea what would cause the truck to heat up like it did? Maybe it was just plain too hot out? I dunno, I just had the coolant flushed/replaced a few weeks ago so my cooling system should be good and I would think that revving the motor (pulling more air through radiator) would help cool the motor, not heat it up. Quote Link to comment Share on other sites More sharing options...
90zxdriver Posted September 22, 2010 Author Report Share Posted September 22, 2010 **update** Finally got the truck in for this problem. I took it back to the dealer I bought it from and they said it needed a new compressor and accumulator, over $2,000. Ok. Then they said that because I bought the truck three months ago and have no previous report of the problem that they couldn't do anything about it. I tell them to look in their computer because two weeks after I bought it I brought it back in for this exact problem. They said no I didn't, I told them to look again. Guess what?!?!? I did bring it in, its in their computer and I have the paper receipt too. So they are eating everything including the $200 EVAP purge valve (or whatever its called) that was giving me the CEL. Sweet! I get my truck back tomorrow after about a week. I still think its the low pressure switch because when the A/C is running, its ice cold. But if the dealer wants to replace these parts that have 68k miles on them... who am I to argue??? I Can't wait to get the truck back! Quote Link to comment Share on other sites More sharing options...
wody Posted September 23, 2010 Report Share Posted September 23, 2010 (edited) i'd like to know their reason for replacing the compressor. accumulators and driers do eventually become saturated and will hinder the performance of the a/c system. they should also replace the orifice screen if they are replacing the compressor. Edited September 23, 2010 by WODY™ (see edit history) Quote Link to comment Share on other sites More sharing options...
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