Smoke coming from Heater Connecter only on Start-Up

[Muzimak]

Hey everyone, recently there's been a bad smell coming from the air vents on start up, then it goes away while driving. So I decided to pop the hood and asked a friend to start the car, and there it was, smoke comes out of the connector / harness that connects to the heater (which was later confirmed by the mechanic). The smoke just comes out briefly then stops. So I went to check with a mechanic and said that connector goes to the heater, he simply disconnected it and the smoke stopped. He said I need to buy a new heater he will source it our for me. Anyone care to clarify what's happening here?

I attached and image of what it looks like.

[Clavurion]

Those are water valves regulating the coolant flow to heater core. Did you check the connector plug and pins if a poor contact is causing resistance. You can also measure the valve coils' resistance.

The valves are open in rest state and closed with PWM voltage from IHKA (AC control unit). If temp setting is on max there should be no activation / voltage to heater valves.

[Muzimak]

Thanx will give that a try, what does it mean keeping it disconnected?

[Clavurion]

Originally Posted by Muzimak

Thanx will give that a try, what does it mean keeping it disconnected?

If that wiring plug is disconnected the valves are open and heater core gets full coolant circulation. So it will be warm inside.

[Muzimak]

Can the heater still work? Or it's not safe until fixed?

[Clavurion]

Originally Posted by Muzimak

Can the heater still work? Or it's not safe until fixed?

The heater should work normally. Though at this point we still don't know if the problem is on the wiring just before connector which would cause the smoking even if the plug is disconnected.

[avocet]

What do the pins and sockets look like? If they have gotten corroded and or contaminated that might be causing some resistance.

And if you can, pull back the wire sheath and see if the wire insulation is burnt/melting.

I am going to assume your mechanic gave a cursory inspection to see if there was any external electrical issue. Did he do any troubleshooting with a meter?

An internal short would cause that sort of overload to the wiring, but I am surprised a blown fuse or code hasn't occurred.

The fact that it smokes indicates the connector is getting voltage. If the connector is getting a solid ground then it would indicate the solenoid has shorted or there is something in the connector to cause a rise in resistance