mcnaugri

I have an '03 E500 with 4 zone Temp system. It controls the fan speed, etc. normally at 72 degrees but the air is ice cold. You can put the temp to HI and it will still be A/C full cold. The outside temp is reading normal. This thing started about a month ago when the back seat controllers had no effect and it blew extremely hot air from them. I kept moving the temps back and forth and cycling power off to the temp unit and it started back working. Now, all 4 zones have the cold air. Also, last night the night illumination lights for the temp system stayed on even after 10 minutes. I had to unplug the battery to reset that. Any ideas? thanks...

Benzo1999

I have the same car with the same problem. I just purchased the car & found it!!! What have you discovered?

Any help is appreciated...Thanks,
Roy in Chicago

konigstiger

Heat exchanger shut off valve part #A2118320584 needs replacement.

Benzo1999

Thanks for the tip!!! $40.00 later & I'm just waiting for the car to cool down, I'll let you know how it works out.

R

Benzo1999

Good call, that was it. Fourty bucks at the stealership for the valve & one hour in the garage & the heat is back on. It was a fairly straight forward install; the only catch would be the removal of the plastic cover (don't break it).

Thanks for the tip.

Diesel Benz

You must be a handy DIYer, for others there would have been detailed info on the task that you found a bit difficult while others have seen a show stopper.

Benzo1999

Yes, I am handy though it really was not too difficult a task. If you can change your own oil or wiper blades you'll do fine. As I mentioned, the only tip I have is to be carefull with the plastic cover when removing it. The rest of the job was very basic.

The worst part about my story is: I finished the job & was telling my wife how great if felt. I think I even mentioned how the car was perfect. We got in the car to run an errand, started it & pulled out of the garage, only to hear my right/front airmatic strut fail!!! OUCH!!! After a few explatives I pulled the car back in to verifiy & yes...it is the strut (oil sprayed on the fender liner) I do plan on removing & replacing it my self...I'll keep you all posted as of tomorrow.

Roy in Chicago

Benzo1999

The valve is located under the windshield wipers cowl cover. If it helps here is the step by step process:

1 remove wiper arm assemblies. just unbolt them from the base, they remove easily.

2 Unscrew the plastic cowl cover (6 plastic screws) & gently pop it loose from the windsheild.

3 Remove the wiper motor assembly (3 mounting bolts) disconnect electrical connections.

4 Now you're ready to access the valve. MB uses special clips that slide off the mounts with now special tools.

5 Remove & replace the valve.

See...Not too tough.

I hope this helps

mcnaugri

I appreciate everyone's help...

gnma

Thank you Konigstiger and Benzo1999 - awesome thread. Anytime you can fix a prob. for $40 its bliss! mcnaugri - good luck with the fix.

Benzo1999 - sorry about the strut - I've read about this issue a few times. Did you get the "car is too low, visit workshop, etc" message?

aceman

Am i experiencing symptoms of the same cause?

The AC seems to have a mind of its own. Sometimes, it will just not blow any air for appx 2-3 minutes (mind you, its been fing hot in the NE), other times its fine. I turn the HVAC off / on a couple times and then by shear luck it works.

Again - its hit or miss, but in this heat - i need it fixed!

let me know what you guys think.

thx

Aceman

Barry45RPM

If you are talking about the fan not working when the system calls for "Max cool" output, or when you put the defroster on, there was a known problem with the blower controller module somewhere under the passenger side of the dash. (Since it's so hot now, when you start the car it immediately calls for the max blower speed.) Mine (in my '04) had to be replaced 2 times to get to a good working controller module installed & never had the problem again.

konigstiger

Agree with Barry sounds like the blower motor and regulator need replacement. Mention P-B-83.25/76c SEPT07 for warranty repair. Under high demand, the blower shuts off, and then attempts to restart. With manual adjustment, the blower shuts off and then restarts. Once the blower shuts off, cycling the ignition may allow the blower to operate.

jjmacj

My problem is that my 1999 C280 fans blows but it is not adequate to cool the car. The problem is not with the coolant, but rather the fan. Help!

Diesel Benz

This question does not belong to this old thread, I'd suggest you to ask from the forum that deals with your car model.

But how did you conclude that it is the fan that prevents the car from cooling even if it is blowing well (you don't actually say it is blowing well but you neither complain about the fan not blowing enough or stopping at a high speed setting which you should have complained if it was an issue)?

You do not need coolant to cool the car, lack of refrigerant would be an issue.

spinn

my problem is that the driver's side temp is cold at 72. I have to turn it up to 85-high before I get any heat. I had the heat exchange valve changed last year which gave me heat to front and rear, but this has been a lingering issue.