Looking after Aircon

[Weso]

Delighted with the automatic air con on my 2004 ZT V6. Last 2 cars i have owned had non working aircon, in both cases terminal...

Any tips on keeping it working long term, following thoughts?
Keep it on all the time?
Use it sparingly?
On or off whilst starting car from cold?

Appreciate there is a mpg penalty running A/C,
Currently ice cold so all well at the moment

Thanks in advance

Mark:}

[Petetourer]

The worst thing for car A/C systems is being turned off for long periods of time.. I try and leave mine on as much as possible.. :shrug:


If you don't want to do that, then make sure you use it at least once a week for a good period of time.. This prevents any seals from drying out and possibly causing leaks...

There's my 2 pence worth.. :D




Delighted with the automatic air con on my 2004 ZT V6. Last 2 cars i have owned had non working aircon, in both cases terminal...

Any tips on keeping it working long term, following thoughts?
Keep it on all the time?
Use it sparingly?
On or off whilst starting car from cold?

Appreciate there is a mpg penalty running A/C,
Currently ice cold so all well at the moment

Thanks in advance

Mark:}

[MrDoodles]

Mine never goes off, even in Winter!

Don't forget that it also dehumidifies the air in your car as well, so keeps your windows clearer when it's damp!

[pevil]

My 75 as probably does yours has climate control and as such I would assume it's designed to be on all the time, indeed the handbook says it will not be able to maintain temperatures as well on eco, not wanting to hijack the thread my main concern is with the fan being on all the time, what's peoples thoughts on that.

[MrDoodles]

my main concern is with the fan being on all the time, what's peoples thoughts on that.

As long as you've fitted one of Jules' updated fan resistors, it should be fine!

[pevil]

Mine is a two speed without the resistor, how do they fare?

[Tinyflier]

I leave mine running all year round too.

I have only recently noticed, but it may ALWAYS have been so, that my air con "hums" (I don't know what the tune is before anyone asks...!).

Turning it off - renders total and absolute silence inside the cabin.

Anyone else notice same?

David

[pevil]

There is no such thing - it is either a 2 speed with resistor, or a three speed. Some fitted with resistors had the resistor hidden.

No need to make any special arrangements for starting the car with a/c, just start it. I leave mine on year round, apart from turning it off when in summer I open the windows. In winter it dehumidifies the air.

Left completely unused, the suggestion is that the seals can dry out and the refridgerant lost.

Now I'm confused :shrug: it was my understanding that 1.8 cars were only fitted with 2 speed fans and having had the fan off the other day to fit a new condenser there was no sign of a resistor, if 2 speed fans always have a resistor then is it a 3 speed? looking at another post on here the cowling would suggest my fan is for a V6. looks like second picture,


The same cowling is on the 1.8 and the diesel in as it as no lower slats either side .

Diesel & 1.8 petrol cowlings and fans
http://i39.tinypic.com/2i8ku21.jpg

2.0/2.5 petrol cowlings and fans
http://i49.tinypic.com/vyo3o6.jpg
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so how can I find out for sure what fan I have?

[chipsceola]

Mine is a two speed without the resistor, how do they fare?

Being a 1.8 your has a 3-wire 2-speed fan if it doesn't have a resistor, the 2-speed with gold resistor is a direct swap, though if you don't want to discharge and regas you'll need to cut away the shroud around the air con pipes to remove and refit.
Chips

[SD1too]

Sorry,but if you don't have the resistor (clearly visible through the front grille) then you have a three speed fan ...

There is no such thing - it is either a 2 speed with resistor, or a three speed.
Guys, please be careful with fan advice, there are many traps waiting to catch you out. The statements you have both made are incorrect.

Early 1.8 engines had two speed fans without a resistor. 3 speed fans were never fitted to the 1.8 engine. Pevil has a 1.8 car so he is probably right to say that he doesn't have a resistor, and his fan is 2 speed.

Simon.

[MrDoodles]

Guys, please be careful with fan advice, there are many traps waiting to catch you out. The statements you have both made are incorrect.

Early 1.8 engines had two speed fans without a resistor. 3 speed fans were never fitted to the 1.8 engine. Pevil has a 1.8 car so he is probably right to say that he doesn't have a resistor, and his fan is 2 speed.

Simon.

Sorry, wasn't aware of that, so have removed post! :bowdown:

Apologies for any confusion caused. :(

[pevil]

Simon, do we know how reliable the early 2 speed fan without resistor is in comparison to the later 2 speed, I'd like to run my C/C most of the time but the fan is my concern, thanks.

[beinet1]

Guys, please be careful with fan advice, there are many traps waiting to catch you out. The statements you have both made are incorrect.

Early 1.8 engines had two speed fans without a resistor. 3 speed fans were never fitted to the 1.8 engine. Pevil has a 1.8 car so he is probably right to say that he doesn't have a resistor, and his fan is 2 speed.

Simon.

Yepp.

Easiest way to check, is to look at the fan motor wiring. 4 wires = old 3 speed, 3 wires = old 2 speed fitted to the 1.8 engine, 2 wires = 2 speed later type with resistor.

The fan motor runs constantly on low speed when the A/C is activated which I think migth be the reason for its short life.

I recently re-brushed my 3 wire 2 speed fan which brougth the low speed back to life that never worked as long as I have had the car(now 100000 miles). I expected to see the fan running at something that could be called low speed but experienced that the low speed was something like 80% speed. There was only a sligth difference between low and full speed regarding fan RPM and noise. I guess that the later resistor fan or the kenlowe fan migth be better regarding this??

Advice on the A/C as mentioned above, but it seems to me that A/C systems in general needs to be serviced / topped up every 3-5 years as there will always be some refrigant loss over time.

[stagn8]

As matter of interest does having the aircon on all the time make much difference to fuel consumption? I know that driving the aircon pump and powering the fan is going to use a bit of power but how much and would it be noticeable?

I remember the first car I had with aircon increased tick over rpm when the aircon came on as it took a lot of power but I assume things have moved on and this isn't such an issue.

Cheers

keith

[SD1too]

Simon, do we know how reliable the early 2 speed fan without resistor is in comparison to the later 2 speed ...
The brushes on the later 2 speed motor (with resistor) should, in theory, last twice as long as those on the original design (because there are two pairs wired in parallel). If you use the air conditioning only when required (including monthly maintenance use during cold weather) from my own experience you should expect about 50,000 miles from your current fan motor before a brush wears down to nothing.

I expected to see the fan running at something that could be called low speed but experienced that the low speed was something like 80% speed. There was only a sligth difference between low and full speed regarding fan RPM and noise.
The 2 speeders running a low speed seem to be much noisier than the 3 speeders. MGR gives rpm figures only for the diesel, so that's a subjective view.

As matter of interest does having the aircon on all the time make much difference to fuel consumption?
In theory, any load on the engine will have a fuel penalty, but is it too small to measure? I believe so. I keep track of my mpg and have never noticed a pattern of increased fuel consumption when air con. is in use.

It's odd how many people ask that question yet they don't seek out the cheapest petrol/diesel, drive in an economical fashion, or walk short distances in preference to using the car.

I remember the first car I had with aircon increased tick over rpm when the aircon came on as it took a lot of power but I assume things have moved on and this isn't such an issue.
That's still the case Keith. The ECM takes care of increasing the idle speed.

Simon.

[Parker]

When I had the 1.8 the aircon was on constant, never had an issue with the fan.

[SD1too]

Did you have an original or a resistor system?

Simon.

[stagn8]

Cheers Simon, I did think that may be the case.

Have to say I seek out the cheapest diesel and use my maxi scoot for short journeys (if it isn't raining anyway because I am a whoose when it comes to rain and bikes!!)

Thanks again

Keith

[HarryM1BYT]

Sorry, wasn't aware of that, so have removed post! :bowdown:

Apologies for any confusion caused. :(

+1

Also removed/ deleted.

[Unclefista]

Mythbusters did a test and found the extra fuel used for running the AC was around the same as used for overcoming the extra drag from running with Windows down.

IIRC

[Xtra100]

How do I know if my air con works or if it needs regassing? I've not used it since last year and it doesn't seem to be cold at all now?

[phenonix]

If one is leaving their air con on all the time do you just turn the ignition off with the Aircon on?
Then when ignition is turned on again it start automatically?
Someone once told me the was bad to do, is it?

[SD1too]

How do I know if my air con works or if it needs regassing? I've not used it since last year and it doesn't seem to be cold at all now?
If the compressor doesn't engage when auto is selected, take it to an air con. specialist or book a home visit from a mobile company. They should attach a gauge set to observe the operating pressures, or evacuate your system. Both methods will reveal the refrigerant charge you have. You've almost certainly lost it. The air con. should be used about once a month, all the year round.

If one is leaving their air con on all the time do you just turn the ignition off with the Aircon on?
Then when ignition is turned on again it start automatically?
Yes. That's how the system is designed to work.

Simon.

[HarryM1BYT]

If one is leaving their air con on all the time do you just turn the ignition off with the Aircon on?
Then when ignition is turned on again it start automatically?
Someone once told me the was bad to do, is it?

It retains the settings you last used. It is designed to just set and forget, I only turn mine off (via eco) when I have the windows open. Normally I just leave it on Auto all of the time.

[phenonix]

I was thinking more along the lines of it blowing a fuse or some other kind of ecu damage by turning the ignition off while the aircon was on.

[al_dente]

Seems like a waste of fuel to me, driving round with the air con on permanently.

I probably use mine about 1% of the time. I switch it on for 5 mins every now and then, just to keep things working OK.

Eco setting is the way to go. :cool:

[Simon.h]

Seems like a waste of fuel to me, driving round with the air con on permanently.

I probably use mine about 1% of the time. I switch it on for 5 mins every now and then, just to keep things working OK.

Eco setting is the way to go. :cool:


Did you know that if the outside temp is about 10c lower (in winter) that the temp you set on the climate control pannel the a.c thinks 'well the outside air is cold so no need for me to cool' and turns itself off.

[MrDoodles]

Did you know that if the outside temp is about 10c lower (in winter) that the temp you set on the climate control pannel the a.c thinks 'well the outside air is cold so no need for me to cool' and turns itself off.

Fantastic, I didn't know that! :bowdown:

So it effectively had "intelligent" air-con, amazing for a car designed in the early to mid Nineties! :)

[beinet1]

Fantastic, I didn't know that! :bowdown:

So it effectively had "intelligent" air-con, amazing for a car designed in the early to mid Nineties! :)

The "A/C shut down outside temperature" is a bit lower. it is typical around 3-5 deg C.

[ProfDave]

It retains the settings you last used. It is designed to just set and forget, I only turn mine off (via eco) when I have the windows open. Normally I just leave it on Auto all of the time.

agreed; mine on auto the whole time; no window mist ever and never (touch wood) been regassed even at 90k

removes dampness that comes in on your shoes too; obviously if it starts to blow less cool then it probably needs gassing and my view on that is to get it done at a garage you trust rather than trying the Halfords home kit! Done that on my Japanese camper

[SD1too]

Did you know that if the outside temp is about 10c lower (in winter) that the temp you set on the climate control pannel the a.c thinks 'well the outside air is cold so no need for me to cool' and turns itself off.
Hi Simon,

That was a theory in the early days but I have carried out tests which disprove it. When the exterior temperature was 3.0 degrees C and the ATC target temperature set between 17 and 20 degrees the compressor engaged and the radiator fan triggered.

MG Rover tells us that the compressor will run when the engine is prepared for the extra load. That could involve many factors, in isolation or in combination (for example coolant temperature, ATF temperature, electrical loads such as the HRW, etc). It's likely that the program used is complicated and we will probably never get to the bottom of it.

But I'm sure that it's not a simple link with exterior temperature.

Simon.

[SD1too]

The "A/C shut down outside temperature" is a bit lower. it is typical around 3-5 deg C.
This doesn't seem to be true for the 75/ZT system. Jules did a test when the outside temperature was 0 degrees C and his a.c. operated between ATC target temperatures of 'LO' and 16 degrees. Mine has also operated at exterior temperatures of 3.0 and 3.5 degrees.

Simon.

[Simon.h]

Hi Simon,

That was a theory in the early days but I have carried out tests which disprove it. When the exterior temperature was 3.0 degrees C and the ATC target temperature set between 17 and 20 degrees the compressor engaged and the radiator fan triggered.

MG Rover tells us that the compressor will run when the engine is prepared for the extra load. That could involve many factors, in isolation or in combination (for example coolant temperature, ATF temperature, electrical loads such as the HRW, etc). It's likely that the program used is complicated and we will probably never get to the bottom of it.

But I'm sure that it's not a simple link with exterior temperature.

Simon.


Cheers for the inf, i learn something new everyday!