Ah-ah-ah. Naughty naughty. Firewall is no longer a legal word to use in conjunction with automobiles since they don't stop fire, or really even slow then down. It is now, legally, a bulkhead. Us old fogies know it and love it (hate it?) As a firewall.
But, yeah, that metal wall separating passenger and engine compartments. If it has a heater control valve, it should be just inside the engine compartment on one of the heater hoses.
Sunday, January 1st, 2012 AT 4:46 AM