A/C not blowing cold after total engine replacement. 2007 Yaris

In January I had to replace my engine in a 2007 Toyota Yaris.
Last week we had the first day, since the engine replacement, that I needed to use the air.
The fan blows air, it just isn’t cold.
Could this be anything to do with the engine replacement? Maybe they didn’t hook something up properly? Do the drain the coolant to the ac when they take out the engine?
I have been reading that it may simply be a fuse or needs to be charged.
I realize I should have checked the a/c when I picked it up, but at -8 below, air conditioning doesn’t cross your mind.
Thank you in advance for any advice.

Engine replacements can get done without opening up the AC system. But: 1) there may have been a reason to open it up for this engine replacement, and it’s possible that it didn’t get recharged. 2) even if the system is left intact, many parts of it still get jostled around quite a bit and with 8 year old components it would not be weird if a leak got itself going. This wouldn’t be anyone’s “fault” - AC systems eventually leak. 3) it is also possible that it’s something as simple as a bad power connection for the AC compressor, or that it was unplugged and not plugged back in. 4) it is also possible that the engine replacement has nothing to do with it, and that the system is 8 years old and leaky.

Your only realistic option is to have someone check out the whole system. I would start at the shop where the engine was done just in case it’s something simple or they can verify something like having discharged the system and not recharged it. But generally, I wouldn’t expect to end up being able to lay it on them.

Many cars require the A/C to be discharged and partially disassembled to do an engine removal. I believe your car is one of those. If the temp was that low (-8), the A/C cannot properly be recharged. If they did try to recharge it, it is probably way low on charge because it was so much colder. I’d take it back and ask them to finish the job and finish charging the system. I had to do the same just past Jan replacing a heater core. I was only able to partially charge the A/C due to the cold. Once we had a good 75º day, I was able to finish charging the system.

BustedKnuckles is correct about the low temps and inability to properly recharge the system. That thought had not occurred to me. Although, if all of the work was done inside of a heated shop, that might not apply. You should certainly ask.

Thank you all so much, I don’t want to place blame, I just want to get it fixed. I will call them and see when I can get it in.

Did you ask the shop who replaced the engine about this? They may have simply forgot to tell you at the time that they had to disassemble the AC and it would need to be recharged once the weather warmed up. It is also possible the AC clutch isn’t coming on b/c they forgot to connect some connector or another. A mechanic can tell you straight away just by popping the hood if the AC clutch is working or not.

In any event make sure the shop you take it to has someone there w/expertise on Toyota AC. It used to be if the AC was too warm you just recharged it with a kit you buy at Walmart. AC systems are much more complicated and finicky now, and doing something like overcharging the system can do very expensive to repair damage. The proper way to recharge now for many newer AC systems is to completely empty the system by pumping all of the refrigerant into a temporary tank, weighing it, adding enough for the proper fill weight, then pumping it all back into the car’s AC system.

Also, just curious about the motivation to replace the engine. Oil leak? Timing belt failure? I sort of like that Yaris and have heard it is a pretty reliable ride. So I’m surprised you had an engine failure so soon.

Have the air conditioner freon charge checked. If they tell you the freon is present then you may have a wire connector that was left unplugged during the engine job or possibly an unrelated component failure like a bad magnetic clutch relay.