Hi all, I'm in the process of trying to eliminate issues with my air con.
The clutch is not engaging but the light comes on when pressed on the console.
I have replaced the head control unit and still have the same issue. I have checked the fuses they all look fine..question here is can a fuse look fine but still be bad? Or does the wire need to be broken in the fuse for it to be dead?
The heater/cooler fan is working fine..erratic speed but I guess that's nothing to do with the clutch not engaging.
The compressor spins fine by hand.
Just trying to cross things off before I go for a evac and refill to see if it's a low pressure cut out.

Thanks
Ed

 

Check a fuse with it in place, both test points should read the same, either 12 or 0 volts.

 

Zero volts means a blown fuse ? You have to spell it out for us dummies.
Ignition on.

 

In some rare cases, a fuse is in a circuit that is at a 'float' voltage, then goes to ground when active.
The 'float' voltage is unknown, as it represents the state when nothing is connected.
Usually, a fuse passes 12 volts in a car, so both little test points on top of the fuse should measure 12v, or whatever the current battery voltage is.
If you read 12v on one side of a fuse, and not on the other, then that is a blown fuse.
You can see the two test points in this picture :

 

Thanks guys. Sorry but do I need the ignition on? So a good fuse flows the 12v's straight though It I take it hence having 12v either side?

 

yes, good fuse has 12v on both test points.

 

You can test the A/C clutch by putting 12v directly to the clutch. Open the Large black plastic box that houses the RCM, BCM and ECU, on the front wall of that box is a connector that the control module inside the car connects to the clutch. Disconnect the two halves of that connector and jump a wire direct from the positive pole of the battery to the A/C clutch. I have done this, but I have forgotten the colors of the wire. You can hear the clutch engage if it is working properly. This test bypasses all the sensors, so you can tell if your clutch is bad or something within the system is causing the A/C compress to fail to run. You can find all the pertinent info in the service manual beginning at in section 24 page 49.

 

Fantastic thanks for that. I'll try it as soon as it decides to stop raining!

 

You must live in Birmingham ENGLAND, not Birmingham ALABAMA.
No way is it raining in Alabama today, just hot, 93 deg F.

 

Haha! Yes you are right! Wish it was 93 degs here!
Actually it's not too bad. Just every time I go out to do anything it starts raining again! Think I need to claim my folks garage for cover!

 

Hi Guys, just thought Id follow this up for anyone else who may be having a aircon issue.
I visited the garage where I usually take my cars for any work to get the tracking done (it was well out) mentioned the aircon issue and the mechanic said it's probably just lack of gas..I wasn't so hopeful.

Anyway he hooked it up to the aircon machine and the was absolutely nothing in it. He run vacuum and a pressure test and it kept pressure for 5 mins solid.
Refilled with gas and it kicked into life. Compressor working, rad fan working, icey cold aircon. Very happy.

Thanks for all of your replies to my question.

 

Well, happy for you, but if all the gas leaked out once, it will happen again until the source of the leak is found and fixed.

 

Hey! Yeah that's what I thought - I guess 5 mins holding pressure is not very long...I'll see how it goes.
Although he did say it may have leaked out due to O-rings drying out if it hadn't been used in a while and that the gas/oil that was going back in would make a seal again.

 

No, when I vacuum down an A/C, I like to watch it for 24 hours, or at the minimum 2 hours.
You should see 27-28 inches of vacuum, and that should not change ANY.

 

Yeah, I will keep my eye on it, see what happens.

On another note - now the tracking has been done (4 wheel) it has made the car feel brand new, feels so tight now compared to what it was.
I asked him what he thought may have knocked the tracking out so much and he suggested it may have been calibrated incorrectly the last time it was done.

 

Normally, alignment ( tracking ) gets off due to curbing or potholes.
Age and wear also contribute ( ball joints etc. )
With this new alignment, you should now also change out the steering stabilizer.

 

Steering stabilizer? Not heard of that but i'll look into it. Thanks.

 

It is the shock absorber looking thing just below the drag link in this diagram :

 

yeah thanks for that. Was just looking into it. Seems easy to replace. May do it soonish then.

 

It's so easy a caveman can do it, IF you turn the wheels to the left just a bit