Jump to content
View in the app

A better way to browse. Learn more.

300ZX Owners Club

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

I have just noticed the air-conditioning on the Zed I bought two weeks ago is not working.

 

Any ideas on what is the most likely cause?

 

Dave

  • Replies 40
  • Views 1.8k
  • Created
  • Last Reply

Top Posters In This Topic

Featured Replies

is the belt fitted (looking at the engine its the right hand lower belt)?

It may have been removed.

  • Author
is the belt fitted (looking at the engine its the right hand lower belt)?

It may have been removed.

 

Yes, the belt is fitted (to my 1995 Zed). I have compared with my 1990 Zed (which I still have and the a/c works fine) and there is a quiet 'click' and the engine changes speed slightly.

 

This doesn't happen on the non-working 1995 Zed although the light on the switch comes on.

 

Could it be a faulty switch? Fuse blown - where do I look? A/c pump knackered - is this likely?

 

Dave

Why would anyone remove the belt if the compressor wasn't knackered?

 

Sounds like it needs re-gassing. Does your irle rpm change at all when you turn it on and off?

more than likely want a regas, sounds like the pump is cutting in ok.

  • Author
more than likely want a regas, sounds like the pump is cutting in ok.

 

Sorry Paul but I don't think the pump IS cutting in. The 'click' etc. I described was on my 1990 Zed, it does not happen on my 1995 Zed where the a/c isn't working. Any ideas?

 

Dave

  • Author
Why would anyone remove the belt if the compressor wasn't knackered?

 

Sounds like it needs re-gassing. Does your irle rpm change at all when you turn it on and off?

 

Hi Clarkey - No, the idle speed does not change when I turn it on/off, neither do I hear a 'click' (which I do on my 1990 Zed). Any ideas?

 

Dave

Yep, if the gas pressure is too low the compressor won't engage to prevent damage.

Why would anyone remove the belt if the compressor wasn't knackered?

 

Cos some of us dont actually want such a power sapping unneccessary extra on our cars. :nono:

There is another option and that is that the relay has been removed. It should be in the engine bay fuse and relay box... on the right hand wing as you look at the car. I had to do this to my old NA when the electro-mechanical (I think) Clutch packed up. Probably isn't that but just in case....

 

HTH

  • Author
There is another option and that is that the relay has been removed. It should be in the engine bay fuse and relay box... on the right hand wing as you look at the car. I had to do this to my old NA when the electro-mechanical (I think) Clutch packed up. Probably isn't that but just in case....

 

HTH

 

Thanks stricker - I've just checked the relay and it works in my 1990 car so should be O.K.

 

Quote Clarkey - Yep, if the gas pressure is too low the compressor won't engage to prevent damage.

 

Hi Clarkey - I didn't realise low gas pressure would prevent the clutch from working. I have looked closely and the clutch is definately not engaging. What's involved in getting the gas pressure up?

 

Dave

What's involved in getting the gas pressure up?

 

Dave

You will need to get the aircon regassed, find a garage advertising such services. Depending on usage this tends to be required every 2-3 years.

 

Unfortuntly the zed uses R12 gas, which is no longer (legally) available in the UK. It can be converted to R134a cheaply though.

 

Aircon regas FAQ : http://www.300zx.co.uk/forums/showthread.php?t=33691

There is always the fuse, very near the relay that you have already checked.

5 amp I think...

if the pressure is low, short out the 2 wires to the low pressure switch, the compressor should then cut in. if it does, the rest of the system is ok & needs a regas (or switch is faulty - unlikely tho ;) )

  • Author
if the pressure is low, short out the 2 wires to the low pressure switch, the compressor should then cut in. if it does, the rest of the system is ok & needs a regas (or switch is faulty - unlikely tho ;) )

 

Thanks Paul - excuse my dumbness but where/what is the low pressure switch and what is best way to short out the two wires?

 

 

mgh297 - I've checked the (10A) fuse and it's O.K.

 

Dave

Cos some of us dont actually want such a power sapping unneccessary extra on our cars. :nono:

 

come on now, with the a/c off that pulley spins compeltely freely, extremely small amount of drag. And if you didn't want it, you would just throw the whole lot away and be done with.

Thanks Paul - excuse my dumbness but where/what is the low pressure switch and what is best way to short out the two wires?

 

 

mgh297 - I've checked the (10A) fuse and it's O.K.

 

Dave

 

on the reciever/drier IIRC, i think you can gain access through the headlamp panel, its on the left as you look through it.

 

you can short it out with a piece of wire or a split pin

If you got an after market filter, you can easily access the pressure switch through the air filter panel.

 

Spent fooking ages sorting my air con out, never found the problem, went through everything with a fine hair comb and never found it. Ended up wiring in a switch myself.

  • Author

I'm really grateful for the help you are all giving me regarding my a/c problem and, because of your help, I have been able to eliminate several possible causes.

 

But I'm afraid I am getting a bit out of my depth when you refer to items such as "low pressure switch" and "receiver/drier" as these things mean nothing to me. I am reasonably useful with my hands and am sure I could cope with things that don't require too much stripping down but if I can't identify the items I am completely lost (and useless). Is it possible to provide a photo or diagram that would help me locate this switch?

 

Dave

Look through your bumper and you can see your rad. Jsut to the left is a black cylinder about 6 inches long, 2 inch diameter. Theres a black plug on that with two wires to it, one orange, one green. Bridge that out with a small piece of wire and if it runs its low on pressure.

 

But I found my tags in the switch had broke and needed soldering back together.

  • Author
Look through your bumper and you can see your rad. Jsut to the left is a black cylinder about 6 inches long, 2 inch diameter. Theres a black plug on that with two wires to it, one orange, one green. Bridge that out with a small piece of wire and if it runs its low on pressure.

 

But I found my tags in the switch had broke and needed soldering back together.

 

O.K. I have found it now but how do I get at the leads to bridge them? Do I have to remove the trays underneath and does the engine have to be running for the a/c clutch to work or does it only need the ignition on?

 

Dave

 

ps. my cylinder is aluminium colour and it has a label on it stating that R134a is to be used. At least that sounds like good news.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Terms of Use

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.