This is a picture of its location on a U.S. car.

 

Now I need to DIVE under the dash and see if I can find the A/C evaporator Temp. sensor!!!!!!!!!!!!!!! The FUN never ends!!!!!!!!!!

 

Now I need to DIVE under the dash and see if I can find the A/C evaporator temp. sensor

Note: on a 79 degree F day my evaporative temp. sensor read 47 degree F.

Please read MY 00 SL500 climate control baseline readings and the attached PDF and here is a picture of the location of the evaporator temp. sensor.

 

Thanks Lynn, I ordered and installed a new Evap temp sensor a week or two ago and have not had a chance to get out on the road and see if its cured. REALLY BUSY with family things!!!!! The sensor was easy to find, with the good pic's I found after doing some digging!!!! The readings I got after replacing the sensor (in diog.mode) were MUCH better than with the old sensor, so my guess is that I will be all set!!!! Thanks EVERYONE!!! for your help!!!

 

I ordered and installed a new Evap temp sensor a week or two ago and have not had a chance to get out on the road and see if its cured. The sensor was easy to find, with the good pic's I found after doing some digging!!!! The readings I got after replacing the sensor (in diog.mode) were MUCH better than with the old sensor, so my guess is that I will be all set

Paul, what was your car exhibiting before you installed the A/C Evaporator Temperature Sensor, p/n 2108300772 for $40.46 at AutohausAZ.com? Would you please point me to the pics that made it easy to install?

 

In My car the A/C would work fine around town, once on the highway for 30-60 minutes I would notice that the fan speed would keep going up(towards high speed) and the interior temp was getting warmer(above the set temp.) This lead Me to believe that the Evaporator was frosting up. Apon putting the A/C system into dianostics mode, The Evap. temp sensor was reading WAY away from what it should have been. ( It should have read 35-40degrees and it was like115 degrees) The sensor is VERY EASY to find and replace, Remove the lower carpeted section of the dash just to the left of the steering column, (hardest part of the job) Theres a phillips screw hidden between the top of the carpet and the parking beake release lever, and a small hex screw under the edge of the panel down towards the throttle pedal. Once you remove that panel, The sensor is just behind the edge of the console. It is the ONLY thing there with 2 SMALL wires in a wire connector that just plugs into the sensor. It took Me about 10min. to finish the job!!!! Lynn, If you need help with it, give Me a call!!!! Sorry I couldn't remember where I saw the pic's

 

you said to the left near the parking brake but in the picture its to the right of the steering column... now im confused

In My car the A/C would work fine around town, once on the highway for 30-60 minutes I would notice that the fan speed would keep going up(towards high speed) and the interior temp was getting warmer(above the set temp.) This lead Me to believe that the Evaporator was frosting up. Apon putting the A/C system into dianostics mode, The Evap. temp sensor was reading WAY away from what it should have been. ( It should have read 35-40degrees and it was like115 degrees) The sensor is VERY EASY to find and replace, Remove the lower carpeted section of the dash just to the left of the steering column, (hardest part of the job) Theres a phillips screw hidden between the top of the carpet and the parking beake release lever, and a small hex screw under the edge of the panel down towards the throttle pedal. Once you remove that panel, The sensor is just behind the edge of the console. It is the ONLY thing there with 2 SMALL wires in a wire connector that just plugs into the sensor. It took Me about 10min. to finish the job!!!! Lynn, If you need help with it, give Me a call!!!! Sorry I couldn't remember where I saw the pic's

 

As far as I know the evaporator sensor is where the picture says it is.

Regards,
aam.

 

Some people are saying that it's on the left under the carpet by the e brake... My car is a 99 maybe they moved it? Now I'm lost I ordered the part from Autohaus az for 40$

 

Don't worry about it, the right location is there... the sensor has to sense the evaporator temperature, but not from three feet away, not that it can not be done, but why?

Paul is a very knowledgeable guy.
Maybe he made a mistake, we all do.

Regards,
aam.

 

Do you guys have some type of info on how to do the repair myself? In the pic it looks like u have to remove the dash or something? Thanks again guys

 

Sorry to say this but if you read the above posts all the information is already there.

Yes, you have to remove the carpeted piece, known as the bolster, just above your right and left knee, under the steering wheel. You should then be able to see where the new part goes by the right knee.

Please keep us posted if you find any of the above information that needs to be corrected.

 

ok, can't believe I need more help but I cannot find the Evap sensor. I've got the carpet off below the wheel and have been on my back for the last 15 minutes trying to find the sensor. I can't see it! My car is a 99 sl500 and from reading the above posts it should be an easy find but I can't see it....I've looked around where my right knee would be, right of the steering column but nothing.


What am I missing? Can anyone give me a more "detailed instructions" to help me out.:bowdown:

 

R129 A/C Evaporator Tempurature Sensor location

My car is a 99 sl500 and from reading the above posts it should be an easy find but I can't see it....I've looked around where my right knee would be, right of the steering column but nothing.

What am I missing? Can anyone give me a more "detailed instructions" to help me out.

After you figure out where it's located please come back and tell us how you found the A/C Evaporator Temperature Sensor, p/n 2108300772

The PDF says, "located in the air flow behind the evaporator in the A/C housing".

 

Thanks for the help.

I think my problem is that I don't know what a evaporator looks like or a A/C housing. I was hoping I would see the old one and unplug and plug in the new one.

Will the sensor be "enclosed or inserted' into something or just plugged in and stay open to the air?

 

I don't know what a evaporator looks

Replacing an Evaporator is a really time consuming job.
Please see http://www.benzworld.org/forums/3645469-post43.html

 

just looking to replace the sensor....Anyone else able to help?

Been looking through other MB sites and now understand that I'll only see the back of the plug rest is inserted. Can anyone tell me the color of the wires that go into it so i can follow them?

 

Sorry for the confusion, once the carpeted cover is removed, I got down on My knees outside of the car, If you look about a foot behind the Radio and AC control on the drivers side of the the Transmission tunnel about 18-20 in off the floor, you WILL see just the end of the sensor sticking out of the A/C-heater housing!!!! Its the ONLY thing right there with any wires going to it!!!!! Your '99 is JUST LIKE MINE!!!! I know the sensor is right there. Most of it is sticking INSIDE the A/C box, only about 1/2 in. is visible. I believe that the sensor just pulls out of the side of the the box. (Its been a year, and I forget stuff) If you still can't find it, Let us know and I will TRY to post some pics Tomorrow. (REALLY busy and leaving town for a couple of Days) GOOD LUCK!!!!!!! I think the wiring to it is BLACK?????

 

Thanks for all the help everyone. I was finally successful in finding the sensor and replacing it. The key on my car was that i also needed to remove the black panel that was located directly above the pedals to see the sensor.

 

I have the black panel in the way as well. It appears to be held in place by the 2 hexagonal screws that I removed to take the carpeted piece out and a screw next to the gas pedal, and that last one is not coming out. I am afraid to use force since it looks like a really flimsy pice of plastic.

Any help is appreciated.

 

OK, NOW for the BIG question!!!! Does it work better???? Hope so, Glad everyone could help!!!

 

That is the question......I only drive it around town so will have to wait till I go on road trip when it is on for an extended time. Did run a diagnostic using the head unit and the number now comes in the correct range. Previously it was way, way off. So i'm hopeful it has been completed correctly. Thanks again.

 

If the # look better, I'm sure you will be all set, Mine did the same thing, It now works PERFECT!!!!!!!!!

 

I ordered the A/C evaporator temperature sensor from AutohausAZ. Price was $40.46 plus $10 for shipping. A $50 order has free shipping so I found a Microfiber Body Shine Duster for $11.35 and added it to the order . Almost free.
Order came in yesterday and just finished the install today.

Using the post as a guide, installed the sensor, it went as planed.

Tried to take some pictures - hope they help

1) Removed the fasteners holding the carpeted cover under the steering column.
3 each -Phipps head screws, the first one on the left you need to pull the parking break release out to access the screw. The others are easily accessed
2 each - hex head screws - use a 8mm socket. Pic. #1 & #2

2) Now everything just drops down.

3) Using drags1998 description as to the sensor location I found it. As he said just the back end of the sensor is showing. I am pointing the screw driver at the location of the sensor. Right side of the steering column. It’s above the floor air vent. That is the vent opening behind the screw driver with the deflection plate removed. Pic #3

Pic #4 is the original sensor before it was removed. See wires going to it.The sensor is just pulled from the box.

Thanks for the help guys - hope the pictures help the next person w/install.

 

Many thanks for these clear instructions. It brought my system back to normal.

Note that there is a Heater Core Temp Sensor p/n 1268301772 (straight-not bent in a dog leg) more directly behind the radio cluster (but on driver's side also). It is a two lead device, but not dog legged like the offending sensor. In picture #3, it would almost be visible at about 2:00 o'clock from the tip of the screw driver.

 

Note that there is a Heater Core Temp Sensor p/n 1268301772 (straight-not bent in a dog leg) more directly behind the radio cluster (but on driver's side also). It is a two lead device, but not dog legged like the offending sensor. In picture #3, it would almost be visible at about 2:00 o'clock from the tip of the screw driver.

Does it look like this Heater Core Temp Sensor p/n 1268301772 ?

 

Ah yes, thanks for identifying it.

 

I recall a plastic flange that engages a metal bracket near the engine compartment that keeps the black plastic from dropping on the brake paddle. pull the plastic toward the seat. The hard part was getting everything to fit back with the A/C hose to the door panel connected.
Good luck. remember old plastic breaks!!!

 

Yeah, that plastic flange took a lifetime to come out, then the black plastic panel slid towards the seat and dropped down.

Now I am having trouble disconnecting the old sensor from the wire coupling.

Slowly but surely I will get there.

Just out of curiosity, the old (I assume original) sensor is slightly different from the one ordered from AutohausAZ isn't it?

 

Mine was also a little different, Thats OK, It will work fine!!!!!! Mine has worked GREAT since changing I did it!!!!

 

Yes mind was different too. Same kind of shape but the original one I took out seemed to have a plastic guard cover around the sensor node (you can see part of it from the picture). Here are some pictures I took (already uploaded to a similar thread).

 

Thanks all for the details here. I replicated the evaporator sensor replacement in my 99 R129. After the dealership did not diagnose the issue and charged me $130 for the non-fix!