2000 bonneville heater core ploblem - 2000 Pontiac Bonneville

where is the valve located under the dash where is the valve located under the dash

Probably too late now, I haven't checked this in a while. It is under the console behind the knobs for the temp/a/c, etc. The valves are inside the housing but you can see a white round circle with what looks like a flat head screwdriver slot in it. That is the valve. You can watch it while you turn the temp knob back and forth to see if it moves at all... If it moves only slightly, then tap it to loosen it up. Hope this helps. Probably too late now, I haven't checked this in a while. It is under the console behind the knobs for the temp/a/c, etc. The valves are inside the housing but you can see a white round circle with what looks like a flat head screwdriver slot in it. That is the valve. You can watch it while you turn the temp knob back and forth to see if it moves at all... If it moves only slightly, then tap it to loosen it up. Hope this helps.