Heater weirdness...

[Mark Rinker]

Wondering if the outside temp sensor is used by the heater control to determine outside / heated air mix?

When I drive with snowplow on, the outside temp indicated on the rearview mirror is always wrong, reads 10-15F too high. Have noticed that during these times, the vent air temps seem to get cooler, for any given setting on the heater display.

Maybe its using that incorrect reading, and getting confused?

[JohnC]

Conservation of energy. If the sensor gets warm, your feet have to get cold.

;)

[joed]

According to my alldata,there are several trouble codes associated with the HVAC system.

Also it talks about recalibrating the system (usually only done when HVAC module is replaced) - either with a scan tool or without by:

Alternate Method (w/o Scan Tool)

1. Clear all DTCs.
2. Place the ignition switch to the OFF position.
3. Install the HVAC actuator.
4. Connect all previously disconnected components.
5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds .
6. Install the HVAC/ECAS fuse.
7. Start the vehicle.
8. Wait 40 seconds for the HVAC control module to self-calibrate.
9. Verify that no DTCs have set as current DTCs.

Just a thought.

Joe.

[Kennedy]

Wondering if the outside temp sensor is used by the heater control to determine outside / heated air mix?

When I drive with snowplow on, the outside temp indicated on the rearview mirror is always wrong, reads 10-15F too high. Have noticed that during these times, the vent air temps seem to get cooler, for any given setting on the heater display.

Maybe its using that incorrect reading, and getting confused?


Om my 2005 I run the SS cold front year round PLUS teh Boss V plow. When the stats open I see as much a 100°f air temp observed and YES the feet get cold.

I have just begun the search for the proper location for the temp sensors. I had extenders built and plan to do some more testing Thursday when I travel to plow the cabin driveway. There are two sensors. One is for the mirror and one is HVAC. My guess is that the HVAC looks at ECT and OAT and determines air door position to get it's targeted (calculated) air temp.

[Kennedy]

I'm not 100% sold on the location that I have them in, but MUCH better. I now see a 10-15°f difference and the HVAC takes this in stride and keeps my feet warm. When Slowed and plowing I did see an increase in the spread, but it seemed to handle this better as I am sure the cowl temp was also up compared to traveling down the highway.