[poppawheelie2]

Does the 453 have a sight glass in the ac line? If not, how is refrigerant checked? A/C worked fine last year. Now blows no cold air at all.

 

[Bob Ricewasser]

Just a guess but since you admit to not using your a/c since last year, it is possible that some of your R-134a leaked out and the compressor is not coming on. Best way to get your system back in action is to have it recharged at a shop that has an R-134 charging station and can leak check your system. The A/C system should be turned on frequently, event in winter, to keep the compressors seals lubricated and prevent this sort of thing from happening.

 

[OliverB]

If the defrost is used periodically in cold weather the AC compressor runs. My 453 was made 5 years ago this month. AC still is properly cold in this 90+F weather. Never looked for a sight glass. If the system is truly low you need to find out why.

 

[poppawheelie2]

Just a guess but since you admit to not using your a/c since last year, it is possible that some of your R-134a leaked out and the compressor is not coming on. Best way to get your system back in action is to have it recharged at a shop that has an R-134 charging station and can leak check your system. The A/C system should be turned on frequently, event in winter, to keep the compressors seals lubricated and prevent this sort of thing from happening.

As OliverB says, the defrost was used numerous times over the winter and the AC kicked on. So anyway, I'll try a local shop before making the long trek to Pittsburgh, the closest Mercedes dealer that will work on it. I think they have a good reputation with Smart. The local Mercedes dealer (State College, PA.) is worthless for anything but sales and turns up it's nose at Smart.

 

[OliverB]

As OliverB says, the defrost was used numerous times over the winter and the AC kicked on. So anyway, I'll try a local shop before making the long trek to Pittsburgh, the closest Mercedes dealer that will work on it. I think they have a good reputation with Smart. The local Mercedes dealer (State College, PA.) is worthless for anything but sales and turns up it's nose at Smart.

For normal AC service any good shop should be able to check coolant charge level and for a leak.

 

[poppawheelie2]

For normal AC service any good shop should be able to check coolant charge level and for a leak.

I just hope it's not the freaking computer. It does blow hot air when I crank the temp up.

 

[jwight]

Have you checked the thermocouple connection in the passenger footwell?

 

[poppawheelie2]

Have you checked the thermocouple connection in the passenger footwell?

What's it look like?

 

[jwight]

Sorry, that's on a 451...

 

[poppawheelie2]

Sorry, that's on a 451...

OK. Thanks anyway. 🙃

 

[poppawheelie2]

Problem solved. Local shop said AC charge was just a little low, enough to stop compressor. Works fine now. Has leak detector die in it if problem persists.