I just had a refill of the A/C on my '87 230CE, changed from freon to some new cooleant.

For the first few weeks the aux fan would start after some minutes with the A/C activated.
The little glass on the dryer did not show any bubbles.

Now, the aux fan will not start, and the dryer glass bubbles.
I have not tried to short circuit the hi-pressure switch for the fan yet. But, could the boiling be due to the fan not running, or is it most likely the fan not running due to low pressure?

Guess the latter is the fact... Will check.

So... Where do I start? Is this a thing I could sort out myself, and if not, will it most likely be too costly to be worth it?

When the cooleant was refilled/changed, the system was tested with nitrogen and vacuum, and showed no sign of leaks within the 4 hours this lasted.

And, by the way, my car has only one electrical fan. Is there supposed to be a low-speed mode of this as well? When it worked, it only ran at one speed (quite fast).

ALL tips and hints are very welcome :-)

PS: Allthoug I live in Norway, we DO have some days demanding an operational A/C! :-D

Anders Eklo - Norway.

anders - Sounds like a leak has come up over the past couple/few weeks - especially if you are getting bubbles in the site glass. This is an indication of not enough refrigerant which can prevent the fan from coming on and if the system is working properly should keep the compressor clutch from engaging. Take it back to whoever you had do the conversion and get them to hook the gauges back up to determine the pressures. Also, if they put dye into the system, they should have a black light and will be able to readily spot the leak.

You have lost refrigerant. It won't be long before the low pressure switch kills the compressor altogether. The fan should have two speeds. Take the good advice previously offered. Get it checked.

Leakage like yours is hard to find. Good luck.

David

Brrrrrr in Norway
 

Brother of The Benz, aeklo
I was of the opinion that in Norway you lowered a window for natural A/Cing.
Even though you only use the A/C a few times a season, this type of service is the worst on the system.
Running with a partial charge of refrigirant leaves a major portion of the compressor oil in the evaporator and damage can occur to the compressor.
Have the system recharged to optain operational condition; then have the leak isolated and repaired.
You in Norway and me on the Gulf of Mexico have oposite seasons yet the A/C is still desireable.
Happy Trails Beep Beep from The Spiderman in Houston, Texas USA!!!

It's gonna cost me...
 

Well folks, thanks a lot for your tips :-)

Guess I'll have to start saving up some money...
Paid $100 just for the conversion, and I can hardly start thinking of the costs for discovering the leak...

It is obviously a small leak. The system was tested with vacuum before being refilled, and showed no sign of a leak during the 3 hours of vacuuming.
The system has been operational approximately 1 month before quitting on me. Guess it'll be both hard to find and costly...

Two final questions though: Since my fan doesn't run at the "slow speed mode", there couldn't possibly be any connection with this and the lack of refrigerant?

And secondly, where do I look to make my fan operate at low speed again? And when is it supposed to run at low speed? All the time when the A/C is enabled?

Thanks a lot for your help!

Anders Eklo - Norway.