A/C troubleshooting.

Nissan 350z / Nissan 370z technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
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mrwrolguy
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Joined: Sun Nov 26, 2017 2:39 pm
Car: 2004 White 350z Touring Edition

A/C troubleshooting.

Postby mrwrolguy » Fri Apr 05, 2019 10:03 am

After putting my new engine in my car last year, A/C worked fine. It played freeze out daily.

1) AC compressor clutch engages after turning on AC switch

2) System is full of freon

3) When AC compressor clutch engages both fans are blowing. After Car warms up.

4) Checked relay/fuse

5) Heater works correctly all vents blow in the direction via the climate control knob.

I was going to run Consult 3 and the laptop took a dump I guess 2 much moisture. I dont even know If I could pull codes off the system?

6) No check engine lights, Car runs like a scalded dog.

Any gurus out there... I am breaking open my service manual after posting this. I will also follow up on the solution as I did with my previous 350z issues/build.

Thanks for any Input. :ohno:


amc49
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Joined: Mon Jun 19, 2017 7:24 pm
Car: '11 Versa
'17 Altima

Re: A/C troubleshooting.

Postby amc49 » Fri Apr 05, 2019 12:09 pm

I for one cannot tell what is wrong there, maybe you should say directly. All you say is that everything is working but the title suggests otherwise.

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mrwrolguy
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Car: 2004 White 350z Touring Edition

Re: A/C troubleshooting.

Postby mrwrolguy » Fri Apr 05, 2019 12:46 pm

Exactly... It should work... I ran the AC test on page 52-60 on the FSM on only thing different was on step 2 its says the light should blink appox 25 seconds.. Mine blinked 11 secs. All the AC meter controls work as they should and all the test say nothing is wrong... but still get Hot air... Im trying to figure out if... AC compressor kicks off and on as it should by hitting the AC button.. I guess maybe the white box under the radio went tits up for the AC portion of the unified meter?? or the thermostat on the cold AC side is bad ( dash knobs ) ... If I turn the thermostat knob from cold to hot it feels like fire coming out of the vents. Tested the actutators they are functioning and the sensor test for ambient air and cabin air all pass also. Ill keep digging.... I thought troubleshoooting a bad ECM and IPDM was difficult thats nothing compared to this microprocessor under the radio :facepalm: Ill update with as much info and I figure out this new problem.

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mrwrolguy
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Car: 2004 White 350z Touring Edition

Re: A/C troubleshooting.

Postby mrwrolguy » Fri Apr 05, 2019 2:05 pm

Completely spinning my wheels without diagnostics... I ordered another replacement laptop or the same kind so I can just replace the harddrive only and my Consult 3 will work again. I had no idea the AC pulled 4 different sensor information just the tell the unified meter its ok for the AC too turn on... Getting to be hot weather and I want my AC working. I will update as I get info... Not a hit and runner. :biggrin:

amc49
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Joined: Mon Jun 19, 2017 7:24 pm
Car: '11 Versa
'17 Altima

Re: A/C troubleshooting.

Postby amc49 » Sat Apr 06, 2019 11:23 pm

If compressor is coming on and STAYING on long enough to cool then I would be looking quick at whether the air mix door was working correctly. You seem to say it gets hotter so working but what if it gets stuck trying to seal 100% of the heat out? A small heat leak quickly overwhelms any strong a/c cool.

You can have 'freon' and yet not enough, the cool doesn't work until past a certain psi of pressure, you give no numbers. I say because the most likely fault there is leaked refrigerant as the car sat not using a/c.

Yeah, that silly electronic LAN overlay there is enough to freak anybody out. You have to reduce the problem by thinking of it all in 1965 purely mechanical terms and ways, the systems really still work the exact same way. Compressor must be on solid to cool and then blower working with proper doors open and proper ones shut as well. For cold a/c, intake doors shut but max a/c door open to correct and air mix door closed off 100% to any heat at all.

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mrwrolguy
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Car: 2004 White 350z Touring Edition

Re: A/C troubleshooting.

Postby mrwrolguy » Sat Apr 20, 2019 1:31 pm

It turns out the system was full of air and a little freon... System was leaking at the high pressure scrader valve... So I replaced both scrader valves high and low pressure... vacuumed down the system for a hour and let set at -30 for a hour.. No change in bars after vacuum ran... Added 2 cans and it was 75 degrees out side and system only cooled too like 55 degrees.. added 6 more ounces and AC kicked in and dropped to below 30 degrees. So solved my problem. Just sharing. First time AC repair only spent 100 bux on gauges and vacuum pump and 3 cans of freon. Not too bad for a first timer. I followed CHRISFIX instructions on YOUTUBE good video. If anyone ever reads this. :dblthumb:

amc49
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Joined: Mon Jun 19, 2017 7:24 pm
Car: '11 Versa
'17 Altima

Re: A/C troubleshooting.

Postby amc49 » Sat Apr 20, 2019 2:03 pm

Beware that 30 degree thing, if true you will freeze up the evaporator at some point and then cooling drops like a rock and the compressor can damage. You want like 35-40 degrees there.

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mrwrolguy
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Car: 2004 White 350z Touring Edition

Re: A/C troubleshooting.

Postby mrwrolguy » Tue Apr 23, 2019 2:48 pm

Thanks for the heads up. I know what too do now... dam sure dont wanna break anything.

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mrwrolguy
Posts: 83
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Car: 2004 White 350z Touring Edition

Re: A/C troubleshooting.

Postby mrwrolguy » Sun Jun 14, 2020 6:23 pm

following up on a final repair... every since the build the ac never worked 100 percent Finally repaired competely.. replaced expansion valve under dash... new compressor and a new dryer and condensor... good solid 41 degrees out vent on 90 degree day. Finally repaired.

kcin117
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Joined: Wed Aug 26, 2020 10:37 am
Car: 2003 Nissan 350Z Touring

Re: A/C troubleshooting.

Postby kcin117 » Wed Aug 26, 2020 9:37 pm

Gentlemen:
Please allow me to share a summer of frustration with you regarding no AC. Early one spring, somewhere about 10 years or so, I did some pm in the engine compartment of my 03 350Z. Cleaned things up, changed some belts and up graded the pulley. Put everything back together and it ran like it was new. Later on however during the first hot spell I turned on the AC on and it blew the air from hell. Got it home checked it out and began what turned out to months of me thinking I actually was in hell. Went over and under the electrical system, pulled and replaced fuses, looked for leaks, sought advice from friends and read up on most Z forums looking for a fix. I then 'rented the AC package' from an auto store for testing the lines etc. etc. All summer long I worked on trying to get cold. Still nothing. Said to myself 'I must be missing something' so I got out the shop book and started from square one to troubleshoot every possibility once again. Late one night I started thinking about what I had read; about reinstalling the clutch plate. I recalled an obscure line about measuring the gap between the two plates that the belt runs through. Measuring the gap? Never heard that before. Got up early the next morning, loosened the bolt and took my spark plug tool, set the gap uniformly 360, reinstalled the belt and bolt, started up the engine and good god almighty I felt the beginning of a cool cool breeze of cold air!! Seems there is an electrical current exchange between the plates, or something to that effect, that is generated from the pulley to the generator. Now my explanation may not be electrically correct but the procedure did the trick. I write this to save others the expense and time that I went through and what.
mrwrolguy may needlessly went through I'm pretty sure that had to be covered with all the other work that had done. Hope this helps someone else out, belatedly as it is.


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