My car is a Ford Focus 2005.
a few weeks back it started leaking and we located the problem, it was from the radiator. My brother and I spent the weekend fixing it, we thought it had cracked but it was only one of the rings that had broken off. we filled it with distilled water and we were supposed to get some glycol on it this weekend, however, there is a new problem.
The car is no longer leaking, but even with the AC turned up max, and it is bowing freezingly cold air, the car gets way hotter than it is outside. The heat is coming from the dashboard where the radiator is located and i’m pretty sure its 60 - 70C.
How would I be able to fix this?
Where is the cold air coming out? Defrost, vent, floor, combination of places? Can you feel the heat being blown out somewhere? Are you sure the housings are all back together properly with no missing pieces or gaps? Is the blend door actuator plugged in and functioning?
More than likely, the temperature control unit for the heater (and A/C, if so equipped) is worn-out. This is the electronic component that you probably need to replace:
You probably don’t have O’Reilly stores where you live, but a local parts store should be able to order something similar for you.
the cold air is coming from the vents as usual, it’s just the dashboard is burning hot when you touch it after driving for a bit. I’m pretty sure we plugged everything in, but I’m gonna have to check tomorrow, a lot of people are saying its the blend door
Dashboards are heated by the sun. Parked cars in my area reach higher than 140 F in the interior of the vehicle. The blend door changes the ventilation air from hot to cold and vice versa.
It’s possible some sort of hvac fault is causing the AC to be on at the same time as the heater. Older cars used a valve to completely shut off coolant flow to the heater in the summer, but modern cars often don’t have that valve. Instead they prevent heat from the heater from going into the passenger compartment using under-dash air-flow routing doors. Maybe one of those doors is stuck and allowing heated air into the passenger compartment. If you were working on the under-dash heater, you may have accidently got the door stuck in the process of finishing.
There may be an easy way to prove this. Do you see two rubber hoses in the engine compartment going through the firewall toward the heater? If so, ask your shop if it is possible for them to temporarily clamp/block the flow in one of those hoses. Then the heater won’t be receiving any hot coolant flow, so it won’t get hot.
When the heater core was replaced, maybe something with the heater core enclosure/box didn’t get lined up correctly, and now there’s a gap somewhere that’s allowing the heat from the heater core to escape to under the dash
