I have been having a nasty time with the AC on my 300TD. When I bought it, it had a very slow leak, and was charged with R-12. I had a small tank of R-12 I found in a yard sale, and recharged it for several months, then I took it to a shop.

There I was told that the tube with the filler valve was the source of the leak and would have to be replaced: price of part: over $400. The system was checked for leaks and recharged with R-12. total cost about $1000. I got about three weeks of cool from that.

A year later, the same shop guy told me I should convert it over to R-134 and check it for leaks with dye. Trusting soul that I am, I did this. Leaks were found, the sight bottle was replaced, more expen$ive parts were found, and then I was told that the auxiliary fan stuck to the outside of the radiator wasn't working, and was assured that this was the ONLY remaining problem. Price of stupid fan: $400. I decided to buy the damn thing myself and install it. I found it finally on e-bay for about $75 delivered. It was made in Taiwan, but it fit fine, after I took the fan parts and mounted it in the old cage and stuck the old plastic shield on it. It was not hard to install, just two easy bolts to the braces in front of the radiator and a bracket and screw at the bottom. The electric cord plugged in easily.

The old fan groans and squeaks when turned by hand. My guess is that with new brushes and proper lube, it could be resurrected.

There was the wing of a deceased songbird behind the old fan and myriad insect wings and unidentifiable bug parts and bits of tiny gravel, all of which I carefully blasted out with a garden hose and pried loose with a plastic nail file.

The AC barely cools. There are no bubbles in the sight glass, and the auxiliary fan does not come on.

My thoughts are that the switch on the sight bottle (yes, I know they call it something else) is shot, and that is why the fan was so squeaky, because it had died of unuse. The shop guy told me that it was only the electric fan, but I tend to think that they really didn't check this out totally. I tend to think that there is an excessive tendency to throw expensive parts at any problem until it starts working.

Can the switch be changed without discharging the system? My guess is no.

What clever ploy can I use to check the new fan? I am pretty sure it is okay, but it might be defective.

Any thoughts will be greatly appreciated.

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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)