yesterday I tried the onboard DTC and got these errors:

EO 33 OUTSIDE TEMP SENSOR
E0 35 OUTSIDE TEMP SENSOR
E0 73 HEAT SUPPLY UNIT COOLANT CIRC. PUMP
E0 75 COOLANT CIRCULATION PUMP

now where do IU find these items on my 93 300se??? and what exactly do these mean???
Am I in for alot of work???

oh and ever since I put in the new blower control regulator I have noticed that not alot of air is being blown out.. for ex.. on max you can hear the blower working pretty hard but the air that comes out of the vents doesnt seem adequate for the amount of noise... what could this be???

Thanks

Hi,

What was the initial problem? Was there no blower? 99% of the time it is the blower motor regulator. When you install a new one, make sure you apply alot of the white dielectric paste on the new regulator. This paste tranfers the heat from the regulator to the blower motor. Thats one of the reason for the decreased life of the regulators. To test the blower motor to see which one is the problem, pull off the thick blue wire on the blower and apply a ground circuit to the blower, if the blower runs at full speed, you just have a bad regulator. As for the codes you pulled, they are just bogus codes and dont apply to the problem that you may be having. If you just installed the regulator, make sure you have the red and green vacuum lines plugged into the proper elements that you remove. The right line should be towards the drivers side and the green towards the right side fender. Hope this helps you out!

Jim LaPlant
Factory Mercedes-Benz Technician

I have experienced the same situation with my blower. It sounds like it is working very hard but I do not get a strong force of air coming out of the vents. I was begining to wonder if this was how it was designed in the 92-93 era since I have seen others post similar problem. In most other cars if you turn the fan to high you get air blowing strongly out of the vents but not in my 92 500SEL, any ideas? What should the system be set to in order to get forceful air coming out of the dash vents?

Thanks
Fred

The first two errors relate to your outside temperature display. If you are receiving a more-or-less accurate reading of the external temperature on your instrument panel then you don't need to worry. Otherwise, if your temperature display is dead or mis-reading, it can be repaired cheap and easy. Let me know if that's the case and I'll brief you on the 'fix'.

Barrie

yes i do get not so accurate readings... what is the fix???

I understand from your last post that you are getting a temperature reading, but that the readings are not very accurate. How far off are they? If the sensor is bad, you will usually not get a reading at all, or it will be waay off.