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My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
Locate and feel both heater core hoses to see with the engine warmed up and running and heater on high heat if both hoses feel warm to hot to the touch and the same in temperature feel.If one feels much cooler then the other this is usually caused by a plugged up heater core needing flushed out or replaced.If you have already replaced the mono valve make sure the valve wiring is o.k.If both hoses are hot and the valve and auxiliary pump were replaced this issue can be caused by a fault with the heater/ac control on the dash itself needing replaced.
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