W140 air con

[219]

Just had the air con recharged at Kwik Fit : their deal is if it doesn't work , you don't pay , and guaranteed for 30 days . Slightly miffed it went up to £59.95 from £39.95 as it was last week , but hey-ho summer is coming .

First branch I went to said it is non essential so they won't do it , next branch , 5 miles further , did it without any problem ; left the car for 90 mins , when I went back they said all good . I paid , went out to the car and tried it , the EC light wouldn't go out , just as before . I went back in and said to the guy it wasn't working . He seemed puzzled , came out , said it had been fine when they had it running ; after a bit of faffing around with the controls , he stopped the engine , and restarted with the EC button held in - lo and behold the light stayed out and icy cold air blew from the vents .

I repeated this on the way home : once started with the button held , the AC can be turned off and back on at will , but if you start the car without holding the button , the light won't go out .

I'm thinking there is a stored fault . I need to go and read up on the blink codes again ( non US W140s don;t have OBD ) I'm fairly sure there will be a way of resetting it .

Anyone on here experienced this before ? Last time I was into blink codes and resetting faults was with my R129 , which is not entirely dissimilar .

 

[BlackC55]

It does have diagnostic capabilities. It has a 32 pin plug. No blink codes.

 

[219]

From memory , it is a matter of identifying a certain blink code , then grounding a certain pin for a certain number of seconds . I had it worked out with my R129 ; just need to do some reading for this now .

 

[219]

It does have diagnostic capabilities. It has a 32 pin plug. No blink codes.

Ah , OK , thanks , it was a 16 pin socket on the 129 . I will do some further reading .

If I can't figure it myself , I'll pop down to Merparts once they reopen ; I know Stef knows the car as he serviced it for the previous owner , and happy to pay his reasonable charge for getting it sorted .

 

[BlackC55]

Most aftermarket kits wont talk to it btw.

 

[BlackC55]

If it hasn't been replaced already. The condenser is probably leaking. Easy to spot when you take the slam panel off

 

[219]

No problem

With the 129 , I was using my old , trusty Avometer 8 and counting the jumps on the needle . Was just on the phone with Stef Mazzoni from Merparts ; he had a thought there is some way of resetting the digital ( later style ) control panel with some combination of button pushes , but hadn't come across this particular fault before .

At end of the day , I have a workaround , and can live with it for now .

Thanks for replying anyway

 

[219]

If it hasn't been replaced already. The condenser is probably leaking. Easy to spot when you take the slam panel off

I had wondered about that , but since it passed the vacuum test before the recharge , I assumed it was probably OK ?

If it fails again within the next week or two , it will point to a leak somewhere .

 

[Will]

Slow leaks don’t always show up on vacuum tests.

 

[Will]

You have to question how the old gas got out of the system if there’s no leaks

 

[Will]

Sorry for the multiple posts - but if you’ve got the late style climate control panel I think you can access fault codes and system data through the panel with a combination of button presses. Service/diagnostic mode.

Did it years ago on 208s and 210s but can’t remember what buttons/sequences involved - used to show system pressure, temperatures, voltage etc and fault codes.

 

[219]

Sorry for the multiple posts - but if you’ve got the late style climate control panel I think you can access fault codes and system data through the panel with a combination of button presses. Service/diagnostic mode.

Did it years ago on 208s and 210s but can’t remember what buttons/sequences involved - used to show system pressure, temperatures, voltage etc and fault codes.

Thanks , I'll do a search and see if I can read up on it . As a 1999 reg car , mine must be one of the last W140s ..

 

[BlackC55]

I had wondered about that , but since it passed the vacuum test before the recharge , I assumed it was probably OK ?

If it fails again within the next week or two , it will point to a leak somewhere .

Vac tests only show up big leaks.

 

[219]

You have to question how the old gas got out of the system if there’s no leaks

Car had been SORN for a year before I got it ; reportedly AC was working when last in use . Could be seals etc , who knows ?

 

[219]

Vac tests only show up big leaks.

I will run it as much as possible while it still works , in case it is a case of seals drying up due to lack of use ? Are there products for AC , as for power steering , to 'soften up' seals and cure leaks ?

Not sure how DIY-able changing seals in AC systems are ? I'm reasonably handy , have done engine swaps , brake rebuilds , carb rebuilds , interior swaps , and numerous other things , more than I can remember right now ...

Away from cars , used to doing reasonably intricate work on electronic/mechanical devices : pro audio , broadcast video ; projectors and more ... and have a reasonable collection of tools .

 

[alabbasi]

If your car is a 99, you should be able to read the codes form the climate control panel without having to go in through the 38 pin connector. I forget how it's done but I've had to do it a few times on my W210's. I bet money that a quick visit to the BW forum will get you the info you need.

Avoid anything with leak seal. It's not good for the system and can cause blockage. Soapy water around all the connections or a quick inspection under the hood (literally on the underside of the hood) for oily residue will likely reveal the source. The big issue on W140 is the evap core which can leak and it's a 25 hour job to pull the dash.

Don't be too miffed at 60 quid for 90 minutes worth of work. Whether your a/c works or not, they have to pay their employees.

Best wishes

 

[grober]

??

K6JRF Auto Page

 

[alabbasi]

Something like that' but i'm not sure if the updated system has different codes. I'm pretty sure the panel is the same as the W210 so take a look there.

 

[219]

??

K6JRF Auto Page

That is more like the panel in my pal's early W220 .

This is mine , with the engine started normally , the EC light is on and the AC won't operate



However , if I switch the engine off , and hold the EC button down before starting , the EC light goes out , and it blows icy cold air



If , once the car is running , I hold down the REST button , the display shows as follows





I will persevere for a few days in case there is a leak , in which case I will go and ask for my money back .

 

[219]

a quick visit to the BW forum will get you the info you need.

Can you give me a link to the forum please ?

I'm not at all bothered about the sixty quid , but they are a national chain and that is their promise .