Help been cleaning and just doing odd some stuff to my new panel. Question here temp gauge only works when it’s warm outside but the digital read out always works. What to change first? No check engine light.

Changed the thermostat still nothing

What thermostat did you use?
These trucklets don’t like anything but an AC Delco 131-158.

A Duralast from Auto Zone with life time warranty. What I don’t understand is my AC still works and the Digital read out hasn’t stopped working yet?

You might be just fine, but it’s a known fact the ECM looks for a certain time frame for the thermostat to open and keep the Dexcool regulated to 180 degrees.
If you get a CEL or MIL light have the code read , if it’s P0128, it’s the Duralast not meeting the ECM’s perameters. It’s just your HHR telling you to put in the right part not the cheaper parts!

If the AC works no codes and the digital read out works. What to change next? The bottom hose isn’t as hot as the top. The bottom one I can hold my hand all the way around it after 20 min drive and digital read out says 189.

Have you changed the Dexcool? It only has a 5 year life, so if you didn’t or don’t know for sure change that

Yes I changed it too it’s good and fresh.

Excellent, so did you burp the cooling system?

https://www.chevyhhr.net/forums/how-...-system-60614/