Unfortunately the 450's were prone to having leaky refrigerant lines and there was even a recall for this.Hello,
My 2006 Smart 450 has 35000miles
A/C dosent blow any cold now, did a few checks, condenser comes on when I press the a/c button and fan is on. Got it refilled and ice cold air lasted 5 days in hot weather thats it. Could not see any leaks. Got it check by mecanic here and he did pressure tests and coulnt not find any leaks, again refill lasted just a few says.
Can someone point me in right direction of what would be doing this?
As your smart was never sold by Mercedes or an authorized dealer thereof in the USA , the only thing you could do is
to order the necessary parts from an international Mercedes dealer (i.e. Canada ) and go from there...
Here's a link to the Canadian smart car site discussing this very problem:
A/c It Works! - Operation and Maintenance: 450 Model, 2005-2006, diesel - Club smart Car