I have spent around $1500 on my A/C and it STILL won't cool. This is on my 1985 300 TD Turbodiesel. One problem seems to be a leak. I replaced the unspeakeably expensive front hose (the one with the valve on it) because the shop told me that the valve was damaged, and had it recharged with R-12. This gave me about a month of cool. I had it converted to R-134a after many assurances that this was the wise thing to do, and according to the mechanic, several leaks were found, the dryer was replaced, and another $900 was removed from my wallet. The shop told me that they were absolutely, positively sure that the only remaining problem was the aux. cooling fan, the one in front of the radiator. Only another $425. After some searching, I found another on E-bay and replaced it myself. It would not turn. I hooked it up with some test leads and it blew like mad. So did the old one, after a shot or too of penetrating oil.

I was then told by a fellow in the parts shop who has an '82 300D that the five-pin aluminum 'ice cube' relay could be the problem. I went to the U-pick junkyard and got two of these, and still it won't blow. I tried connecting the two leads to the climate switch. This makes something (I think the compressor) click, as does plugging in the leads, so I am assuming that the switch on the dryer is okay. I don't see bubbles in the sight glass. I have been told that with r134a, I should see bubbles, so there is probably another leak. The shop guy said that dye was used and that this rarely fails to find all the leaks.

I told the shop guy about his misdiagnosis, and he said to bring it back and he'd spend some free time on it. But I am most interested in having a cool car. What could be the problem? There is also a large black relay-looking device, labeled "Klima", but the parts guy said that these control the compressor. A new one would be very expensive, and there were none I could find at the U-pick yard, though I could look again, they have a pretty fast turnover.

Whatever could be the problem here? I will greatly appreciate any help with this.
I am not ruling out that something was installed incorrectly at the shop.

So I figure that there are two problems: a leak and a fan problem.

The leakage rate is about the same as when I first brought the car to the shop in March of 2006.

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Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)