riannausa

My a/c for some reason has a mind of it's own. it takes forever to cool and turn the compressor on, sometimes about 30mins. im not sure if the problem is my climate control or something else???? Can anybody help me out. I had my freon checked and it's full. It's getting hot here in Cali already and i can't be without a/c. Please HELP!!!

riannausa

suggestions??

MarcusF

Go here, click AC Diagnostics on the left, follow the instructions, write down the codes, and post them in this thread. With the codes, it should be easy to tell what's wrong. It isn't always easy , but it should be.

riannausa

Here you go:

1 74
2 109
3 78
4 78
5 76
6 183
7 1
8 75
9 0
10 3.2
20 0
21 6
22 0
23 100
24 14.1
40 8
41 5
42 232
43 14


what do they mean???

MarcusF

If you did what I posted on my page (20 minute drive w/AC on, let the car idle for 60 seconds while in park with the AC on, and then pressed and held the "REST" button), the compressor isn’t engaging. Compressors don’t engage if the Freon is low enough, but you've said it's full. #7 is the barometric pressure of the Freon. It’s 1. At this point, I'd suspect the hi/low switch. An AC guy can test the switch by jumpering it and seeing if the compessor engages. If it does, it needs a $100 switch

riannausa

u mean my climate control switch is the problem??? or just the hi/low button?? i didn't know you can change just the hi/low buttom itself!! can it be a DIY project?? or i have to purchase a whole new climate control unit. ill try again later after work to see if there's any changes on it. by the way i found a climate control unit with part #2108303285R i thinks it's from an E320 it looks thasame except for the circulate button i think it has a bypass button. its plugs in and works ok i just wanna make sure its ok to use it.?? what exactly is the right climate control part #for clk430?? by the way the #7 what does it mean?? also what i have noticed is that after like 30mins the compressor turns on it turns off again after 10 mins. same thing happens everytime.

MarcusF

Not the climate control (HVAC) buttons. The AC has a high pressure/low pressure switch. It's at the receiver dryer. If the AC tech knows the system is full of freon, and jumpering the switch causes the compressor to engage, it's usually the switch. When you press the AC button, the signal goes through the high pressure/low pressure switch to the compressor relay. If the high pressure/low pressure switch is bad, the relay never gets the signal, and the compressor never engages.

riannausa

so that causes the compressor to also work for 10 mins then turns off again??? ill post the new readings by the way

82
130
77
82
61
194
13
134
-4
5.1
2.0
6
0
0
13.9
9
5
232
14

you think theres anychanges? i got this while the compressor is on.

thank you so much for the help. at least i hope i dont have to get a new climate control unit.

whats the part number by the way?? also the part # for the actual climate control unit.? also will i be able to use the climate control unit from the e320?? thanks

riannausa

i also have a question, where is the exact location of the expansion valve??? any diagrams on this forum?? or picture of what if looks like??

MarcusF

The HVAC controller on my car is 140-830-26-85.

Stand in front of the driver’s side high beam. Look at the ABS pump (It's the square box with all the metal brake lines running into it. The top of the receiver dryer sits between the ABS pump and the high beam. You're looking for a circular metal top with a metal hose fitting that points toward the drivers fender, it turns into rubber, and runs along the driver’s fender. That, and on the left of the circular top is a switch that looks like the one in my post.

BTW, in your second set of numbers, it looks like the AC hasn’t been on very long. The temperature at the evaporator sensor should be close to the in-car temperature sensor while the A/C is off, and a lot lower while the A/C is on. Mine reads 37˚ after a few minutes. Yours reads 61˚. Sounds like the busted hi low switch is turning the compressor off every few minutes.

riannausa

the last reading actually was taken after i ve been driving for about 1/2 an hr. but it was right after the compressor turned on. so nothing on the climate control unit from an e320 if i can still use it??? also, u think my expansion valve and receiver dryer is still ok??

do u have the part number for the busted switch??

MarcusF

I don’t know whether the E320 uses the same climate control unit. It seems like it would, but I couldn’t say whether there are differences from year to year / model to model – and whether those differences would stop it from functioning. What I can say is when I look up the part number I gave you, the description states "2000-2002 HVAC – controls – Dash Control Unit – CLK320 CLK430 CLK55". Also, when the dealer replaced mine, the software was upgraded. Of course, the software may be part of the climate control unit.

I think your expansion valve and receiver dryer are probably still good. I think it sounds like the hi low switch is bad. However, I’m not an AC tech. There may be more to it than evacuating the system/swapping the switch/recharging the system.