Mercedes-Benz Forum banner

21 - 40 of 45 Posts

·
Registered
1998 E320
Joined
·
46 Posts
Discussion Starter #21
Electrical problem figured out. Really it was not electrical at all. A test wire was hooked up to the wire going to the compressor and the system was sending 12v to the clutch. bottom line the clutch was bad. I'm replacing the compressor today. I got the part for $250 out the door. It's a OE denso part. I'm going to my friend's shop tomorrow for refilling the system. I'm leaving the other parts alone. We'll see how it goes. :)
 

·
Registered
1998 E320
Joined
·
46 Posts
Discussion Starter #22
A/C Compressor Relaced. Did not replace the dryer or the expansion valve. Refilled the system after pulling avacuum and holding a vacuum. I filled the system with 6oz of PAG 150 and 3 12oz cans of 134a. Lowest temp recorded at 45mph with recirculate on 47 degrees F. Ambient outside temp was 87 degrees F.

Cheers:D
 

·
Premium Member
2004 CLK 240 Coupe
Joined
·
11,378 Posts
Well done. :)


It's all academic now as you have replaced the entire compressor with its clutch. But for the benefit of others reading this thread in the archives, I'd like to correct an error on my post #18 here where I said no electrics were required for the clutch. This is wrong.

Further study of the a/c circuits shows there is a wire from pin 22 connector 2 on AAC pushbutton control module (N22) to the compressor electro-magnetic clutch on the compressor (A9). This must be going to item A9k1, which your diagnostic reported had failed. :thumbsup:
 

·
Registered
1996 210.020
Joined
·
3,972 Posts
Replacing the compressor without flushing, purging and replacing the dryer will likely amount to a practice run.
 

·
Registered
1998 E320
Joined
·
46 Posts
Discussion Starter #25
I'll keep you guys updated on how long the sytem will work based on just replacing the compressor. I do agree with the proper proceedure of replacing the dryer, the pressure regulator. A flush and a fill is fine. I did what needed to do. Thanks for all of the help from everyone on the forum!
 

·
Registered
Mercedes E320 W210 111 year 2000
Joined
·
9 Posts
Just to clarify some of the issues raised here, because I have been working through the WIS for many models in the past year or so, I have realised a few MB design concepts.

1. Not everything electrical has a dedicated fuse. Often a suspect device is driven from a module which does have its own fuse. The module circuitry acts as a fuse, but you know that the module's own fuse is OK because many other features from the module are still working.

2. Details of the fuse locations (maps/charts) were originally stowed by MB for the owner inside one of the fusebox locations on the car. Most MB cars have at least 3 fusebox locations: engine bay, interior, and trunk. On certain models some big fuses, termed pre-fuses that protect modules or large consumers, are sometimes hidden in a fuse box under the passenger footwell. These will not be found without information that is not always available to a second owner, who may not have the original Owner's Manual.

3. Whereas MB does provide the Owner with details of fuse locations, they do not give details of relay locations, although the box is often called the Fuse & Relay box. Even owning a WIS does not always help with the relays location. Sometimes I can identify a relay on the circuit diagram, but can find no drawing in the WIS showing it's actual location.

4. This thread has raised the issue of a magnetic clutch on the a/c compressor that might have failed. The WIS does refer to this device (but shows no picture) on a document titled: Magnetic clutch at refrigerant compressor overheating, refrigerant compressor does not operate.

Cause: Interference voltage spikes from the Engine Control Module via direct lead on control module. The a/c compressor is switched on & off continuously, causing the magnetic clutch to become too hot and fail.

Remedy: A. Replace pushbutton control module (or) B. Replace a/c compressor.

Let me explain i am new to this conversation but I totally understand why no one is replying with answers. I am having the same problem and nobody understands why the car doesn't have the relays listed etc. You cant find them online because they only list fuses land every vin number has a different chart anyways. As I am reading along I hope to find the answer.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,903 Posts
Let me explain i am new to this conversation but I totally understand why no one is replying with answers. I am having the same problem and nobody understands why the car doesn't have the relays listed etc. You cant find them online because they only list fuses land every vin number has a different chart anyways. As I am reading along I hope to find the answer.
What is your question, please ?
and,
what is the model, and model year of your car?
 

·
Registered
Mercedes E320 W210 111 year 2000
Joined
·
9 Posts
Did you ever find out were the AC Clutch relay is? Even the parts store couldn't tell me and I didn't read an answer. I look up the part online and its the same as the other relays. There is a ground wire that was worn out I replaced and the connection to the compressor itself was worn however still nowhere can I find which one is the relay to test if I need the clutch or compressor or refill freon, rebuild compressor or just replace clutch. But the pressure sensor wont engage the compressor if its to low on freon and thats it theres no getting in unless you bypass the relay and hurry up and pump in the freon. . You cant refill the freon if the clutch doesn't engage so a total catch 22. At 300000 miles I am not paying a mercedes mechanic= 1000 to 3000 to replace compressor, drier, EOE valve,condensor, temp and prressure sensors and flush the system because the cars not worth that but worth it to me to save. If i knew where the relay was I can bypass the pressure sensor and add freon or replace a couple parts (compressor 45 clutch 65) myself. Who wouldn't? At that many miles that engine is better then any toyota or honda I purchased brand new Please respond and thanks.

Are you kidding me? I understand that the compressor is driven by a belt. There is a difference between a fuse and a relay. I want to know which relay to replace for the power going to the a/c compressor's electromagnetic clutch. Are you guys telling me that it only has a fuse and not a relay?
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,903 Posts
For W210 cars, there is no such thing as a "conventional" compressor clutch relay. The clutch is controlled by the climate controller, and a relay function (solid state switch) is inside the controller. The clutch is not turned on and off to regulate the cabin temperature, but it is constantly turned on, whenever the a/c is turned on.

I asked the model and model year of the car, to make sure we talk about the correct climate contrl system.
 

·
W163 and General Mercedes Host
Joined
·
3,222 Posts
Let me explain i am new to this conversation but I totally understand why no one is replying with answers. I am having the same problem and nobody understands why the car doesn't have the relays listed etc. You cant find them online because they only list fuses land every vin number has a different chart anyways. As I am reading along I hope to find the answer.
Please update your user CP info....

click on your icon----> click on Account Settings---->
goto Account Details----> add vehicle details---->
ADD your make model YEAR ----> click save
 

·
Registered
1998 E320s sedan and wagon
Joined
·
1,070 Posts
mrboca is your quickest path to resolution. The car itself can likely tell you what’s wrong but mrboca needs to know what car you have to guide you to and through the diagnostics.

Sixto
98 E320 wagon 197K miles
 

·
Registered
Mercedes E320 W210 111 year 2000
Joined
·
9 Posts
My car is E320 year 2000. I was told that it is a direct contact ran by the serpentine belt. I know the temp and pressure sensors both control the compressor. If they say hey not enough freon they cut off the compressor. If the compressor or clutch burn up the serpentine belt will still go but the clutch will not engage no matter what you do. You can try to hot wire the pressure sensor but if the compressor is done it wont engage. My codes did read B1233, B1232, B1418, and B1419 and if I hit a bump the compressor would work This worked for a year or so then it wouldn't. The I put a block of wood on my relays (dont ask some guy on you tube) but it worked for another year. Now its deader then a door nail. Here is the twist I got all codes to clear but the B1419 and for some reason my fuse 20 (50amp) engine fan is dead too. Why? There is no power even coming to the wire but there is power at the fan. How is that possible? How is there power at the fan but at the fuse box nothing. Makes no since. HELP!!
 

·
Registered
Mercedes E320 W210 111 year 2000
Joined
·
9 Posts
I failed to mention that the connection on my compressor took some abuse since the bottom cover was lost by the tire guys. I replaced this connection (rewired) to have a much tighter fit but this did nothing as well. I did notice that there was 5 rocks in the home of the condenser but no holes visual. FYI. The temp and pressure sensor both are active with power.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,903 Posts
The compressor wiring from the climate controller module ( the module with the display in your center dash) first goes to the relay module at the passenger side under the hood (where fuse 20 is), and is cross connected there and then goes to the compressor. In other words, it is not a direct wiring. So the wooden block on the relay module is to press on a a loose and maybe corroded connector that goes to the relay module which kept the connection going. So any bump loosened the connector disconnecting he compressor wiring. You need to take a close look at the connectors to the relay module (maybe a mechanic can do it for you) and make sure there are no corroded connector (usually due to water intrusion from the channel between the hood and the fender especially if the module lid is not properly installed. The same story with fuse 20 which should be 30 amps anyway.

The fuse 20 may be blown. Visually check it and measure power on both sides of the fuse (the tabs on each side). The fan is not powered by fuse 20. This fuse powers the fan control module which then powers the fan with different duty cycles (pulsed) to control speed. The fan may have power on it but not ground. Else it would have worked, right ? The power may be coming from some other power source that goes to the control module (only when the key is in position 2 (run). You need to make sure that fuse 20 is powered and not blown. Then you can take the next steps.

Make sure that the compressor is well grounded.
 

·
Registered
1998 E320s sedan and wagon
Joined
·
1,070 Posts
IIRC B1419 means open circuit at the clutch. Can you spin the face of the compressor by hand? If not, the clutch circuit probably blew because the compressor is seized. I don’t think there’s a practical way to reset the clutch.

mrboca, I think it’s a 30A fuse for aux fans ahead of the condenser. It’s a 50A fuse for single fan behind the radiator as in ‘00 E320.

Sixto
98 E320 wagon 197K miles
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,903 Posts
IIRC B1419 means open circuit at the clutch. Can you spin the face of the compressor by hand? If not, the clutch circuit probably blew because the compressor is seized. I don’t think there’s a practical way to reset the clutch.

mrboca, I think it’s a 30A fuse for aux fans ahead of the condenser. It’s a 50A fuse for single fan behind the radiator as in ‘00 E320.

Sixto
98 E320 wagon 197K miles
It may mean the fusible link in the clutch coil is open, or it mean the connector or wiring is bad. The poster indicated that the compressor worked on and off, so it is more likely a bad connection in the wire but checking if the compressor has seized will not hurt :).

My wiring diagram shows 30 amps for fuse 20 for both case (with N65+M4 and N76+/M4/3)
 

Attachments

·
Registered
1998 E320s sedan and wagon
Joined
·
1,070 Posts
What I know comes from Saturday mornings at pick-n-pull :)

Sixto
98 E320 wagon 197K miles
 

·
Registered
Mercedes E320 W210 111 year 2000
Joined
·
9 Posts
The compressor wiring from the climate controller module ( the module with the display in your center dash) first goes to the relay module at the passenger side under the hood (where fuse 20 is), and is cross connected there and then goes to the compressor. In other words, it is not a direct wiring. So the wooden block on the relay module is to press on a a loose and maybe corroded connector that goes to the relay module which kept the connection going. So any bump loosened the connector disconnecting he compressor wiring. You need to take a close look at the connectors to the relay module (maybe a mechanic can do it for you) and make sure there are no corroded connector (usually due to water intrusion from the channel between the hood and the fender especially if the module lid is not properly installed. The same story with fuse 20 which should be 30 amps anyway.

The fuse 20 may be blown. Visually check it and measure power on both sides of the fuse (the tabs on each side). The fan is not powered by fuse 20. This fuse powers the fan control module which then powers the fan with different duty cycles (pulsed) to control speed. The fan may have power on it but not ground. Else it would have worked, right ? The power may be coming from some other power source that goes to the control module (only when the key is in position 2 (run). You need to make sure that fuse 20 is powered and not blown. Then you can take the next steps.

Make sure that the compressor is well grounded.
Compressor not grounded and wiring on fan is shot. In fact all the wiring in this car is falling apart. OMG. Thanks for the help. I dislike wiring but gotta do it.
 

·
Registered
1998 E320s sedan and wagon
Joined
·
1,070 Posts
How can the compressor not be grounded if it’s bolted to the block? Maybe a bad ground wire from the clutch to the compressor housing, but you’d have to drop the compressor to see that.

Sixto
98 E320 wagon 197K miles
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
6,903 Posts
Yeah, there is a ground wire from the coil that goes and bolts to the compressor (see the picture at the top of the compressor with a Phillips-head bolt grounded wire).. If removed, or loose, there will be no current flowing, and you will have the 419 code. The compressor itself is grounded by its body bolted to the metalwork.
2639437
 
21 - 40 of 45 Posts
Top