Now that's an interesting config. but how do you determine what valve to open and which one to close and for what purpose? The one going to the core I understand because that is what I did today but what is the other valve for? The tee going to the tank line makes sense because the coolant would than flow to the rad return line.... OK, I get it, when you close the line to the core, you open the line to the return line to keep coolant flowing. When you open the line to the heater core, you close the line to the crossover and it works like the stock config. Brilliant! Do you really need the crossover though? Most stock configs have a heater valve that closes automatically (with the climate controls) and does no harm, but do they normally divert coolant to return as your config does, or just shutoff the line to the core? Wish Alfa had gotten this one right to begin with, really one of the most REALLY unexcusable things on the car, IMHO. And yes my flapper (stepper motor) is working, I checked. Thanks for the pic. Just went to get some gas and nice cool air flowing through the vents (A/C not working right now so I REALLY needed ambient air and not heated air, next project) :rolleyes
P.S.-Went to replace the hose from the bottom of the coolant tank to the rad pipe, well, it is not 3/4" hose like the (to) heater core line - something a little bit bigger, uff da!
'91 164L 5 speed