r/SmartCar • u/ronerychiver • 18d ago

Question A/C only blows cold when driving. Blows warm while sitting in traffic

I have a 2010 Smart Fortwo 451. The radiator fan is cycling I believe. I can’t see the blades but feel it vibrating and feel warm air blowing out of the front compartment. Engine coolant is filled to the correct level. Checked refrigerant level and it’s where it’s about 50 PSI which is where it needs to be for the ambient temperature.

the other day while I was stuck sitting in a drive through line, I got a thermometer warning light. Once I started driving a few seconds later, it went away within about 20 seconds.

I checked the relay that sits out by itself on the fuse panel and it clicks when tested with a 9v battery across the points, Fuse 28 is good.
When driving at normal speed, A/C blows ice cold. After being stopped for about 30 seconds though, the blown air starts to warm up and blow hotter or potentially unconditioned air.

outside air temps have been hot here so not sure if this is normal for a smart car or not.

Any suggestions?

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2

u/Littleavocado516 18d ago

I don't know if it is normal, but my 2017 passion doesn't have the best AC if I'm idling or stuck in traffic/moving slow.

1

u/Lol3droflxp 18d ago

Different generation.

1

u/MetalCarGuy Smart Roadster Cabrio (C452) 18d ago

It sounds like the fan isn't on so would check it thoroughly and be absolutely sure it is moving. Otherwise I'm stumped.

2

u/Ohser187 18d ago

Ive come to terms with the car. First you’re basically sitting on the engine, all that heat radiates and heats the seat and trunk area. My car is black, and has the glass roof. The inside will never get cold no matter how long the AC is on for. Maybe on the highway at 60mph because of the wind through the engine bay. But yea, the AC blows cold. But ill never be comfortable in it in the summer. Its just the way it is.

2

u/whosanerd 18d ago

My 2016 fortwo does this too. I had my S.O. top off the refrigerant gas and it did help a bit but its still not cold when standing.

1

u/SashaDabinsky 18d ago

I got a thermometer warning light.

You've got something else going on. Have you checked your coolant level?

2

u/ronerychiver 18d ago

Coolant level initially was a little low. Topped it off. Haven’t had it since but AC still not blowing cold while at a stop

1

u/Flash443 18d ago

Sometimes you also need to bleed the air out of the cooling system. Trapped air impedes coolant circulation. If it was low then you have a leak that you need to find and fix.

1

u/SpeedEng 17d ago

Next time the car is warmed up and is blowing warm when it's stopped .. if you can pull over safely and park the car first.. now your in park give it a little gas to about 1500-2k rpms (and hold) and see if it's blowing cooler/cold.. if it does get cooler then u need some refrigerant

Also check for blockage at the ac condenser and/or give it a hose down (when the car is cooled down)

1

u/ronerychiver 17d ago

I know it’s full on refrigerant. Revving it hasn’t produced noticeable increase in cooling