Oh, we’re talking about the A/C drain, I was still thinking heater core.
I found it but I can’t get it off. It doesn’t seem clogged, at least not the opening, but I’ll have to try to get it off to be sure.
I was thinking maybe air trapped in the heater core? :dunno: Is there anywhere to bleed the cooling system on these cars? The coolant level was full at the neck, but it was still warm, so I should probably check that when it’s cool too.