Hello all my first post here. Just acquired a '66 C10 with the L6 250 and having heater problems. It appears I'm not getting water flow through the core as evidenced by lack of heat generated and core intake plumbing is cold after engine is up to temp. Wandering if I may have a water pump problem. Here's what I've done so far: 1. Replaced heater motor & squirrel cage. Original motor was frozen up. 2. Cleaned air flow ducting to & from heater core. 3. Flushed core with clean water. A lot of sludge was removed but water flow was immediate. No blockage. Temps here in Michigan have been rather cool and longest drive so far has been 30 minutes. If the water pump was inop I believe I'd get an engine idiot light(if working) and/or coolant overflow. The radiator is normally hot to the touch, so I think there's flow between the radiator and through the engine. Haven't checked hoses for blockage, but will before tackling the pump. Stumped so far... Thx 66FLWB
Charles F Rising JR: check to make sure that the heater control valve is in good operating order as it will not let water flow through the core if it is bad
;-) I've seen this problem many times, check the heater hose's at the water pump there is probly crap in the connector tubes and the hose's.....good luck, rickster from kansas
