Mr. B

Okay… i’ve only had the car about a year… just loving life... but the A/C has always seemed a bit weak… airflow just not strong… sought out the filters… and replaced the 2 dust filters for $17... the 2 carbon ran $100+, so they will wait… never activate that button anyway… it’s improved a bit now but still weak… it gets cold, just doesn't move a lot of air and on really hot days (100+) it just struggles to keep up...

then i read about the great diagnostics capabilities available with the pushbutton controller… the “actual value” function is said to be most helpful..

the procedure for the actual values go like this:
turn on the ignition, press the “AUTO” button, set the temperature on each side to 72*F (this can be done quickly by pressing both the red and blue arrows at the same time), then press the “REST” button for five seconds or until the left side display say’s “1.”
the right-side display will then display the in-car temperature sensor reading. pressing the “AUTO” buttons on one side makes the positions change up or down (for example; 1, 2, 3, etc.). pressing the opposite “AUTO” button runs the functions in the other direction (for example; 3, 2, 1). the test can be ended at any time by tapping the “REST” button


however i’m not sure what to make of the results… these were ran when it was about 95*F outside. see chart below for reference...



1) 35
2) 32
3) 06
4) 07
5) 01
6) 76
7) 11 --- then and cycles and climbs as high as 27... Don’t know why..??
8) 33
9) --
10) 3.9 --- this changes up or down if you alter the fan speed. 6.0 @ max, 4.5 one click down
11) 2.5
12) 3.5
20) 10.0
22) 0
23) 100
24) 12.8
40) 71
41) 36
42) 72
43) 136


can anyone help explain what values would be normal or maybe even run the test and post your results..??


Thanks,

~ Mr. B ~

lexrex

Numbers look good. Weak airflow is almost always caused by a bad blower regulator.

Mercedes revised the blower regulator design to fix this problem. Unfortunately, the updated regulator requires that you replace your perfectly good blower with an updated version. The new style blower motor and regulator together cost about $800. The old regulator, which works with your existing blower motor, is no longer manufactured.

Search the archives for "w140 blower regulator" to find out how you can modify a W140 blower regulator to work in your car for cheap.

E320Star

Agreeee.

Mr. B

thanks so much for the info… this site and all its members are so helpful… like a big extended family… good to have someone to set you in the right direction…

i was kind of on this path myself already… after browsing through my performanceproducts4benz.com parts catalog… i discovered that the regulator was one of the replacement parts they carried… kind of figured at that point, since they don’t stock all the parts needed... if they stocked it… it’s likely to be the parts that happen to break and need replacing… but it also stated it was no longer available… and the replacement from MB USA would require the full motor and regulator swap ($800+)… ouch, wasn‘t looking forward to that…

now that W140 regulator swap/modification fix you speak of… sounds easy enough… searched the forums… couldn’t find a pictured “how-to”… although i found lots of info… thinking I just might make a “how-to” for others… we’ll see..!!

searched autohausaz.com for the ‘97 S500 W140 regulator… they show item # 1408218351 Koehler (KAE) at $163.63 or item # 1408218451 Behr at $214.79 both with free shipping… pictured below… which to use..??

also wondering now… if the original regulators could be repaired..??

i’m thinking maybe a blown resistor is all… since i work for a large electronics manufacturer… that has tons of these type of parts (resistors, capacitors, diodes, transistors, etc.) and some pretty old and knowledgeable electrical engineers that i’m hoping might be able to come up with the fix i need… i’ll pick they’re brains and keep you posted… thanks again for the help.


~ Mr. B ~

lexrex

Get whichever one is not made in France (seriously)

tony

I just ordered the Behr brand based on some recommendations I read in this or another forum. I'll be tackling this job tomorrow or Saturday.

My regulator started to fail by not blowing harder at the highest setting on the A/C console. The marker would move up to the last zone, but the fan would not blow any harder. Finally one day the fan would only blow at what seems to be the lowest fan setting despite the display saying that it is at max fan speed.

I'll keep you posted on how the repair goes.

Anthony_Huynh

Hello Tony,

Please post the result of your A/C fix. Mine has the exact same symptoms you described (except my blower sometimes works for a few secs), the fan indicator is at max but hardly any air is blowing out of the center vents.

Thanks in advance,

AH

tony

I replaced the regulator on my car todayand it worked like a charm. Here is a DIY writeup I just posted on the board. Good luck!
https://mbworld.org/forums/e-class-w210/153918-early-w210-blower-motor-regulator-replacement-diy-here.html

Mr. B

thanks Tony...

parts are in but i won't have any time to actually do the fix until Monday... i'll most likely use either; fully insulated in-line quick connects or maybe Molex pins with heat shrink to insulate when splicing the wires... since i have that kind of stuff at work already... easy crimp and go...

does it have to be soldered..??
are these crimp on, then plug and lock connectors any good..??

keep ya posted as to my progress... for now it's back to party party... took the week off for the 4th. of July


~ Mr. B ~

Mr. B

ok it's done...

i did the modification on mine yesterday kind of as Tony suggested in his "how-to"...

soldered the wires and then used heat shrink tubing to insulate each individual wire… wrapped it all up with some electrical tape and reinstalled...

now it blow’s like mad… i realized it had only been working up to three bars on the climate control display… now at four, five, six bars it progressively gets faster and seven well... it will blow your hat off… well almost… he he he…

it’s truly a great fix… scheduled to do a friends on Thursday for him… and i’ll try to take some pictures of the step by step results…


thanks to all for the help...


~ Mr. B ~

Mr. B

Help..!!

holy cow… if it’s not one thing it’s another… after getting the blower regulator fixed and working like a charm for a week… all of a sudden the A/C doesn’t want to make COLD air…

ran these A/C diagnostic codes: (dash said it was 104*F outside if that helps, felt like 110*)

1 - 37
2 - 48
3 - 15
4 - 15
5 - 14
6 - 89
7 - E
8 - 49
9 - 25
10 - 4.5
11 - 3.0
12 - 3.0
20 - 10.0

any clue as to what the “E” on number 7 means..

i hooked up a gauge to the refrigerant input and it reads as if the freon is with-in the proper levels (high side of blue zone… green being low and yellow high, red danger zone on gauge)

any help is greatly appreciated…


~ Mr. B ~

slk55lvr

Hey I am having the same problem as a couple of you guys, a big thanks to whoever posted how to read these sensors! Here's what mine just read:


1. 78
2. 76
3. 84
4. 82
5. 80
6.84
7. 01
8.76
9. 27
10. 2.3
11. E
12. 4.3

What does the "E" on number 11 signify?

JimPurdy

I had an issue this morning when I had set the thermostats to 72 degrees and the car wouldn't cool. I ran the diagnostics and found that the #3 & #4 heater core temperatures were at 80 degrees F while #5 was showing 40 degrees. I ran the numbers on: http://www.eclassbenz.com/node/27 The result suggested that the Duovalve was sticking. I cleaned the duovalve and now the #3 & #4 readings are within a degree or two of the #5 reading.

Update from this morning's 18 mile commute: The #3 & #4 heater readings were 35 degrees and the #5 evaporator temperature was 33 degrees. I am very pleased with the result after 15 minutes of easy work.