Climate control: LO blows hot?

[Matt Phelps]

I'm having trouble with my climate control system on my 9000. It worked fine for ages after a replacement compressor (about 4000 miles ago) but for the last week I can't get any cold air out of it whether it's in AUTO or manual control.

Setting the temp to LO normally blows cold air at full speed but now it only blows hot air!? Added to that, even when I turn the unit OFF (which, with the window open, is the only way to stop it getting too hot in the car now) I still get warm air through the vents.

Anyone got a clue? This only started happening within the last week since we had all the cold weather. Whether that has anything to do with it I don't know but it's now back to normal January weather and still I can't get any cold air out the aircon.

It's getting very uncomfortable....

[Matt Phelps]

Solved the problem myself. I just did a recalibrate and it seemed to fix the problem. I guess the very very cold weather upset the calibration and it need resetting. Pressing AUTO and <=> together recalibrate the system.

Thought I'd post my solution here incase someone else has the same problem and does a search.

[BillJ]

Originally Posted by Matt Phelps

Thought I'd post my solution here incase someone else has the same problem and does a search.

Thanks, Matt. It's very useful to have a follow-up like this so people know what the solution to the problem turned out to be.
Glad you got it sorted.

[260BHP9000]

Have same "lo blows hot" with my 1994 9000.
Dont know how to re-calibrate, prehaps someone can tell me, but what I do is to remove the offending fuse from inside the glove box, leave for around 10 seconds, replace ( sometimes have to repeat twice) and then push the top left(auto) and bottom right (arrow button) together to re-set and check for number of errors.
If I reset before taking fuse out, it may show 1 or 2 as number of errors, and then go back to blowing hot air on LO setting, If I take fuse out once or twice first, it will show "zero" errors, and blow nice and cold again.
Getting a bit bored with this method , so what is this "recalibration" method please.

Cheers, Andy

[260BHP9000]

Sorry, I read Matts reply properly, realised I have actually described my method which apparently is re-calibrating whoops !!

However, as this is a recurring theme with mine, sometimes it needs doing a few times a week, two days runnning etc, ( i mean needing to take fuse out too) what else could problem be please ??

Cheers,
Andy

[fectoid]

Awesome! I had the same problem and I took my recently purchased Saab to an AC specialist who said that the AC was fine but that something was wrong in the dash and that it would be big money to repair. I found your calibration recommendation and now I have cold air! Thanks

[suckerpunch]

Thought I would reactivate this thread rather than starting a new one. I'm not getting any cooling from the ACC on my '95 Aero. This is annoying with the current weather, as you can imagine.

Over the last couple of weeks I did notice the ACC not cooling, just blowing, but then only ocassionally. As of today it's warm air only. I recalibrated it (twice) as the instruction manual says, but no luck. Because it was intermittent, I thought it was most likely an electrical issue, but of course there's not very much written in the Haynes manual about it.

BPV did a *huge* service on my car last month, including replacing the exhaust manifold studs, and they had to remove the AC Compressor to get access, so I suspected some wiring might have been loose, but it doesn't look like it - everything appears to be in place.

So - any suggestions? Could it be the Compressor is low on coolant? Dead fuse?

I did do a 950 mile trip to Le Mans and back with four people and a full carload through the very hot weekend two weeks ago - maybe the car is protesting

[djtaylor]

Originally Posted by suckerpunch

So - any suggestions? Could it be the Compressor is low on coolant? Dead fuse?

Lets be optimistic and assume that the ACC control system works just fine. When did it last work? was it effective then?

I'm going to sound like an old bore here but there's a low pressure switch that is activated when there's enough refrigerant in the system to pressurise it. That then passes power to the ACC system which will turn on the relay which engages the compressor when required.

In otherwords, if you're too low on refrigerant, nothing will happen so in my mind, getting that checked first is vital. Once you have your known system starting point, you can then start following the electrics.

If you really want to you can try it in reverse, pop a wire from the battery +ve down to the compressor clutch, does it engage? Provide power across the relay coil, does the relay flip? Short out the low pressure switch contacts, does the relay and the compressor clutch engage? (note, if the engine is running, you don't want to do this for long).

When was the system last re-gassed? If you're answer is "don't know" you might want to get that done as the oil is in the refrigerant and low refrigerant means low oil and is only going to accelerate compressor wear.

The other thing that you might want to check first if you have a good feeling about the rest above is the cabin air sensor. There's a little motor/fan combo which draws air past a sensor. If that fan doesn't turn then the sensor doesn't see the right cabin temp and you'll get screwed up results too.

David.

[suckerpunch]

Useful old bore at least

You're right (and so is everyone else) about getting the system topped up first, then at least I know there's sufficient lube and refrigerant. If nothing happens after that, I'll check the sensor and everything else. Cheers for the info.

I'll be using the motorbike for a few days I think