OK, for those of you that have been enjoying my A/C saga, here's a recap- after lots of time troubleshooting and fixing various issues with the duct system on my blazer, the A/C was repaired. It blew cold air. On the coldest day of the year (so far) in Houston, TX (yes, it was a cool 50f), I had A/C that blew through the correct vents and ducts when it was supposed to. The problem was that the heat had ceased to work. So, here is my problem matrix that I need help with: 1. Problem: Heater not working. 2. Remedial steps: a. Removed both hoses from heater core to check flow. No flow from either hose. b. REmoved the hoses: 3. The nipple at the water pump is clear and unclogged-No flow from this 4. Hoses are not clogged 5. The heater core is unclogged and flows freely 6. Replaced Water pump. Still no flow at the heater hose nipple on the waterpump. 7. Thermostat: it is in the closed position when pulled ==> appears to be working 8. Miscelleaneous: Intake has been replaced, I beleive that the original heater hose ran from the back of intake to heater core and not from waerpump nipple to heater core. 9. Anyone have any suggestions? I and my mechanic are at a dead end on this one unless the waterpump is bad. I can't see how there would be a differnence in flow between a nipple on the waterpump and a niple coming off the back of the intake. Any ideas or suggestions?