smartjay28

hey everyone.

heres my problem- AC is not working i have the analog contoller on coldest setting for both zones and it blows hot air.

my troubleshooting:
- checked the fuse (41 and i believe 52 or something like that for the AC related)
-checked the freon level. released some and the recharged back to specification (thought of being overcharged and causing the sensor to 'trip')
-googled for the past 2~3 weeks
-searched everywhere on this forum
-couldnt find "duovalve" on the car nor the forum or google.
-no clicking sounds.
-i learned that there is no clutch for the AC compressor.
-looked at all possible PDF files in regards of AC related and came to a dead end.

any help would do.
Thanks in advance!

bbrain

do you hear the sound of the roaring aux fans?

read about my problem here

it may help you

smartjay28

i read that thread earlier today. so it was your compressor that went bad?

bbrain

thats what they tell me.. if it gets replaced and everything works fine, it will be for sure. hold off till tuesday and i will let you know.

are your fans running at high speeds?

does it blow hot only at idle but cold in motion?

those were my symptons

Glyn M Ruck

What mileage? Sounds like another compressor - What with all the aircon problems on the forum??? Summer???

smartjay28

no cold air what so ever,moving or not.
128k miles on the clock. its an 02 c240 sedan(forgot to mention that lol)

i actually wanna look at the mixing valves. but the thing is, last night i sat in the car in the silent playing with the switches and such and i can hear everything moving around without a problem (vent location, temp, recirc, etc) no click no nothing.

im really hoping its not the compressor.

oh and another note...when i checked the freon level, the low was spiking and high was "low"...that usualy means expansion valve but something else tells me its not. gauge doesnt get effected with engine on or off.

Glyn M Ruck

Refrigerant circuit layout.

capt_paul

My air conditioning went out about 1000 miles out of warranty. Needed a new compressor and related parts. It cost almost $1500 labor and parts, so be prepared to faint.

The compressors are different for different model years, so yours may be more or less money.

smartjay28

Paul- im holding my breath haha.

Glyn- do you have the electrical schematic for the tri-sensor(or w.e mb calls them) (# 20). i would like to jump the sensor to see if thats at fault.

Glyn M Ruck

Yep! R15,000 in South Africa. Expensive business.

OP - I will see if I have electrical schematic - not hopeful & my filing sucks.

Glyn M Ruck

This is all I have - Electrical schematic for the aircon & headlamp washing system. All one harness.

samaritrey

Wtf that is expensive. Now i am really scared my car is 8 years old has 131,000 on the clock and yeah now i am scared. i still haven’t replaced water pump, alternator, and of course ac compressor. if you add all that up that would be alot of money to spend within say a month if i had really bad luck.

ebargados

perhaps you just need a refrigerant refill. i had mine done at 90,000 kms.

smartjay28

thats the first thing i checked. checked if it was over charged or undercharged...no difference.

04c230ksedan

posting because my AC went out not too long ago.
6yrs 42k miles.

One day it just stop blowing cold air, only warm air.
It was the AC condensor on my car.

Cost me $1200 at the dealer.

I did the same as you, and searched every thread here to find a DIY.

fanito

Hehe, this sucks... I hate summer just for the fact that you have 50/50 chance to screw up your AC...

Not to hijack your thread but here's my issue:
My car started blowing not awfully cold air, just ok, it seems that it was working and everytime I added freon it seems that it was working a little better. One day it just quit working at all and now the EC red light is constantly on (and of course, blowing warm air).

The guy at a local oil change shop told me that the problem was the compressor... ughhh. He said that the pressure going out was less than going in or something (maybe it was backwards)... who knows... he took $49.99 from me and did nothing.

Other than another over $1k of repairs what should I do? No DIY for AC repairs here?

Helpy, helpy please

ebargados

my car has been in the shop for over a week now because my ac was blowing hot air. i was told that i had a leak on my condenser. so they ripped my whole dash out to remove the condenser (5.5 hour job). unfortunately, it'll take much longer than that to put everything back. the bill would be roughly $2500 CDN which will be covered by my extended warranty.

smartjay28

bring up an old thread! haha.

i still didnt figure this out yet.

can someone post a diagram or know how to bypass the pressure/temp sensor switch(jumping a wire or 2)? i want to see if thats being the culprit.

smartjay28

Update: its fixed. it was the temp/pres switch. The car ended up leaving me stuck on the side of the road (trans in limp mode) so ended up taking to a Merc shop where they ran a short test. front and rear sam's, temp/pres switch and gas pedal plus few minor stuffs were replaced and a bent wallet lol.

But thanks for all your helps!!

Glyn M Ruck

Good news - same as splinter's a/c problem

amanonfire

Is the temp/pressure switch something that can be DIY'd?

Glyn M Ruck

Yes - but I would get a pro to recharge the system.

amanonfire

Sweet, can you provide some info on how to do it? Thanks in advance!

Glyn M Ruck

See 20 in the diagram: Release aircon pressure at Schrader valves - low side & high side. Unplug, unscrew, screw in new unit & plug back in. Recharge system.

In some countries you are not allowed to vent R134a to atmosphere. It's ozone friendly as opposed to R12 so I don't see the issue.
Good luck!

smartjay28

AC crapped out again end of last summer. I'm going to replace the Pres/temp sensor myself and hope for the best. Hoping its not the front SAM again!

Thank god, this isn't my DD as its been high 90's to low 100's in NJ.