[Eroggen]

Hi all,
I'm new to the forum. I have a 2016 4 door long bed with about 160,000 miles. For the most part I love the truck although it has its issues. Since about 50,000 I have put up with a defroster that is plenty hot when on high, but even one click off high and it will turn ice cold. Has anyone out there experienced this? The dealer has been great trying to figure this out, but is now being told by GM that for the diesel Colorado that is normal operation. So if they can get there hands on another diesel Colorado that doesn't do it, then they can and will go to GM with some ammo to say it is not normal. Looking for any feedback on this issue or if you live anywhere near Sparta MI. I would greatly appreciate the help.
Thanks!

 

[SFLTruck]

Welcome,

Someone will chime in, certainty not me do to my location in FL.....

 

[DmaxGuff]

I wanted to wait until I had a few cold nights to test this, but sorry my defrost is equally hot regardless of the fan setting. Mine is a '16 Colorado Z71.

 

[YukonDiesel]

Can confirm. My defrost is hot on all settings. Why would it be anything but? Blowing cold air on cold windows does not make things better. I do know that there is also an accessory electric heater on high setting, due to lack of engine heat for cold starts at cold temps.

 

[SFLTruck]

Hi all,
I'm new to the forum. I have a 2016 4 door long bed with about 160,000 miles. For the most part I love the truck although it has its issues. Since about 50,000 I have put up with a defroster that is plenty hot when on high, but even one click off high and it will turn ice cold. Has anyone out there experienced this? The dealer has been great trying to figure this out, but is now being told by GM that for the diesel Colorado that is normal operation. So if they can get there hands on another diesel Colorado that doesn't do it, then they can and will go to GM with some ammo to say it is not normal. Looking for any feedback on this issue or if you live anywhere near Sparta MI. I would greatly appreciate the help.
Thanks!

One thing I forgot to mention, your coolant level could be low. The AUX heater works only when the fan is set to max. It could be once that aux heater shuts off from you lowering the fan speed there is simply no coolant flowing through the heater core. This could be from low coolant level or the mixing valve not functioning or the blend door is bad.