My continuing saga to get my HVAC working properly has come down to replacing the sunload sensor part XR836394 on my 2005 STR. It's very slow reacting to temperature changes in the cabin so it blows very hot then the A/C comes on, then it's too cold so the heat comes on etc.
Already replaced the DCCV, had the CCM fixed, replaced the cabin temp sensor so I'm down to the sunload sensor. The workshop manual says after removing A pillar trim, vent trim and unplugging the sunload sensor to remove and discard the instrument panel insulators, these are not shown in the jPart. Anyone know what these mystery parts are, because the manual says they have to be replaced.
Thanks

 

Before tearing apart the dashboard, have you worked through the troubleshooting guide yet?

Climate Control Troubleshooting Guide


Before condemning the solar sensor, don't overlook the possibility of a component previously replaced being bad from stock. Another possibility is a wiring fault, such as a corroded connector.

What happens when you select HI or LO on the control panel? That bypasses most of the automatic inputs, including the solar sensor. You could also leave the system in auto and cover the sensor with heavy tape for troubleshooting.

IIRC, the solar sensor can only tweak the duct temperature a few degrees on one side. If you're getting full hot or cold when the system acts up, the solar sensor is not the likely cause. The controller is not programmed to give the sensor such authority.

 

Check ambient air temp sensor reading against your phone weather temp. Ambient air temp is a data point used by climate control