AC Quits Blowing Cold Air

[netdvn]

Originally Posted by frankgh

How do you get those codes from the A/C. If I understand, you can read then on the A/C control head. What is the secret botton combo to get them to come up?

Frank, Visit following link for the diag. steps .... http://www.continentalimports.com/ser_ic40142.html

Good luck!

[frankgh]

Thanks for the link. I have a 98 E300DT and just had the dealer in Sarasota replace the evaporator core. ($3300). I have since found a good indy mech to help me out. Seems the blower controller is starting to go too. I think I'll fix that one myself.
Thanks Again,
Frank

[netdvn]

www.eclassbenz.com/node/27 povides better instructions.

[SF E420]

Originally Posted by SF E420

Alright fellas, these are great instructions in this thread. I will run out to Walmart and pick up the supplies. Then I will try and perform these steps that you guys provided and report back and let you know the results.

Thanks again! -SF E420

Oh btw, is there away to tell how much R134a are in the vheicle's a/c system?

Okay, this is the results.

1. I bought a bottle of that artic freeze and check the pressure. The system had enough refrigerant.

2. Proceeded to clean the duovalve. Found one plunger with a broken stem.

Does anyone know where I can buy a replacement plunger?

Thanks in advance -SF E420

[SF E420]

Originally Posted by 4maticinmedford

thanks a lot wood'sbenz, i thought i was a little low on r134a so i bought some and went to put it in and the gauge registered full, or blue, correct level, so i figured i needed to clean the duovalve, i took it off and cleaned it out and lubed it, but couldn't get it back on without removing the plug, so i tried to remove the plug and broke two of the little copper wires connecting the coils to the plug!! it looks like someone with very small, steady hands and a little electrical knowledge could fix it, but i will probably have to spring for a new one, $175! My own stupid fault!!

4maticinmedford,

Would you be interested in selling me your plungers inside your Dual Valve? Please email me and let me know! do_cbp at yahoo dot com

Thanks SF E420

[wood'sbenz]

Good luck on finding a plunger only...

You'll probably need to buy a new duovalve assembly. Check eBay or a local salvage yard for one on the cheap. As with most MB parts, the duovalve is rather costly through the parts department of your local Benz dealer.

[chevy4x4]

It sounds as if you added more than one can of refrigerant. when adding the second can (or part of)-is their a risk of adding too much and how can you tell when to stop?

[wood'sbenz]

The system has built-in protection for over-pressurization. If this occurs, the compressor won't engage and you can manually release pressure from the shrader valve at the low-pressure side. I wouldn't be too worried about over-pressurizing, as you're adding refrigerant into the low pressure side with the compressor running.

[Wizard2]

Hi

I did the valve cleaning but as of yet have not put in any refrig.

I must not have tightened the screws well enough and I got a leak of the fluid that was in the res. What is that fluid is it the oil from the 134a or is it something else? If it something else does it need to be replaced I did lose quite a bit because I took the car for about a 10 min. ride? I did retighten the screws.

I have to say so far it did help because I did not get the problem of the system turning hot on that 10 min ride which it would have before this. So hope I stopped that problem for good and I am going to get some 134a and recharge in hopes it will help with the lack of very cold air which was problem 2

Thanks

[netdvn]

The fluid you found leaking at the duovalve is the coolant from radiator. Check the coolant in the radiator and fill it up if it is necessary. Make sure use the Mercedes brand name of coolant.

Good luck!