saabSean

History: I rear ended someone, sent my car to an autobody, they had to replace the radiator support, but not the radiator, ever since my climate control act "funny".

The CC head diagnostic shows 19.04. Our tech article shows that to be a "Specified Fresh Air Blower voltage (Volts)" sporadic short. I had to guess at that because the tech article doesn't really show an error for this channel. There's a good chance that I'm not reading this correctly.

The problem (intermittent). At times, when the car is fully warmed, at idle, the climate control blows cold air. However, once underway, the air coming from the vents is warm. During this situation, once driving, the warm air won't stop. The car becomes very warm and I have to turn it all the way down to "LO" to get relief. So, the fan speed never changes, just the temperature of the air being forced through. Very strange.

My concern is that the autobody is not going to know how to fix this. I'd love to lead them in a direction, so any additional thoughts above what I've listed here would be good.

My best guess is that there is a loose wire to a flap motor or to a sensor controlling the flap, but it would be to something under the hood, not behind the dash. Anyone else want to take a stab?

Kris Hansen

which means, they had to drain the coolant. If they didn't burp it fully, you could have a pocket of air in there, which is consistant with what you describe.

saabSean

But would that be an intermittent issue?

Kris Hansen

it finds places to sit, and blocks the coolant. The reason it gets so hot is because it's not being cooled, or, you are picking up water in your core that was sitting in the same place for a while. It's probably much hotter than the CC unit thinks it is at that point, which is why it's not metering in enough cold air. Get it bled by someone who knows what they are doing.

6ULDV8

Is the sensor correctly installed in the front bumper? Is it good? Is the wiring good? This part is easily damaged in a front hit. You need to run a basic setting to see if the motors are functioning properly and also check the temp sensors. If the car has been through a couple of warm up and cool downs, I would not worry about air being in the system.

Andres G

If there is an air bubble blocking the flow of water through the whole system, how does this alow the extremely hot water to get to the radiator? Kris, your explanation seems a little bit confusing to me... can you run through it again???

From my point of view, this has to be an electrical problem, related to the readout of temperatures, both, inside and outside the cabin. Those are the ones actuating the Fresh Air Blower, arent they? I'd check the wiring diagrams with the Bentley and find whatever may have been disconnected or shorted during the repair.

Andres.

Kris Hansen

that's why it gets so hot. There could also be steam in the heater core, which is much hotter than the coolant which is normally in there.

Also, the air bubble may not be blocking the WHOLE system, just part of it, ie, the heater circut, which is a branch rather than part of the full loop.

Andres G

I guess you mean hot water? If this is it, then I now finally get it!

Kris Hansen

Doh! yeah, hot water.

saabSean

We've been seeing single digits here and that's what the outside temp is reading. I'll keep a closer eye on the temp value though, that's a good point.