Originally Posted by engatwork

I've got the car in that is kicking my butt in regards to making the heater work ( A/C blows cold. Anyway, I've got a known good monovalve installed and even with the wire at the monovalve disconnected it still blows cold whether I am at idle or driving down the interstate. My next step is going to be to disconnect the hoses at the firewall and see if I can blow through the heater core. Any other things to consider while in there. tia