Heater issues

hpedolzky

I am in a love-hate relation ship with this 2005 Explorer. Purchased it for a good price. 2 months later I needed a new engine. While sitting in the shop waiting to be repaired, someone broke in and busted the steering column. Had that replaced, needed the new key programmed to make it work. Got the car back 2 weeks ago worked great for 4 days (still runs good) but yesterday morning the heat wouldn't come on and i had (still have) this clicking noise tick - tick and no heat. The ticking is there anytime, except when i turn the temp knob to AC. I think it's a damper that doesn't flip right, maybe the motor gear has a busted tooth. The temp outside now hits freezing overnight and I really, besides heat, need the defrost to work the first 5 to 10 minutes. My question is is it a module or do i have to tear it apart and find what's klicking.
Thanks for any advice.

Mr_Shiftright

One test you can perform is, after the car is all warmed up, to feel the two heater hoses going into, and coming out of the firewall--do this from the engine side. If both lines are warm, then warm coolant is circulating through the heater core and I'd guess your problem is with a blend door or door actuator that is not opening.

If one heater hose is warm and the other cold, then you may have a problem with the control module and the heater valve that allows coolant to enter the heater core under the dash. Sometimes these HVAC systems will store a trouble code, if you have the type of scanner that can access the HVAC system.

If both heater hoses are cold, then you have a stuck thermostat or are very low on coolant, both of which will prevent you from getting any heat into the passenger compartment.