Just had a shop replace the heater core in my 02 s10. They told me they had to drain the AC to do the job, which is fine by be. When I picked it up they said they could't get it to take a charge but it would hold a vaccum. Then when I drove off the fan only blows out the vents, no selection like floor heat, defrost, combination defrost vent ect. There closed now ? is what do I need to know or ask when I take it back?

 

I've never replaced the heater core but I did not think venting the AC system was necessary.

If you have no control over to where the HVAC air flows, it sounds like a lack of vacuum to the main control switches, either because it was not reconnected or a line was cut/has a leak in it. I believe air coming out of the instrument panel vents is the no-vacuum/fail mode for the system.

 

I've done my heater core and I'm also an a/c technician. I can assure you that the a/c did not have to be drained, nor even touched. The reason for the vent issue is probably a connector that was missed under the dash.

 

In other words, they said they scammed Your refrigerant, is that correct?

Pricey, But they could go even further. I've heard a story of some local shop in my city that had used to collect cars for reparation. Once the car was delivered, they were going to clone the keys and return the car to the owner saying "sorry, we can't fix it". A next few days car was gone...