I haven't really had an opportunity to check out my automatic climate control system in cold weather (i.e. 30 - 40 degrees Farenheit) since I purchased mine in late March. I've been running mine at 68 degrees for the last 6 months and was wondering if and when the coolant will ever flow through the heater core. So, I went ahead and set it for manual operation by pressing the ducts for the floor and window vents, cranked up the temp setting to 90 degrees and placed the fan speed up to max. I finally did got some hot air coming through the vents (below and onto the windshield), in accordance with my manual settings. However, the light for the A/C stayed on (eventhough I would push it off ...it would return). It seems that if you don't do this occasionally, then your heater core will never have the opportunity to cycle the coolant through. Maybe, I'm wrong about this, but it seems that during the colder months I will probably set the temp at 78 degrees on auto, but will this ensure that coolant is flowing through the heater core or not. You know what happens when you don't use the heater...heater cores do tend to go bad and leak. Bottom line: do I need to set the temp up to 90 degrees occasionally to ensure that coolant is flowing through the heater core and not just sitting there? C5 Tech or C4C5 Specialist any thoughts?


[Modified by Mark S., 1:58 PM 9/24/2001]

 

I can't imagine that you need to use the heat during the summer to make sure that it will be fine when it is cooler, but there may be something I don't know. ;)

The A/C will stay on no matter what you do if it is in defrost mode and it is cool out. I don't know what the cutoff temperature is for the A/C to stay off. If you want the A/C off, just set the mode to soemthing other than defrost and you will be able to turn it off. This surprised me too.

 

I think there was a comment about this in the owner's video tape. The A/C is on in defrost mode because it helps dry out the air and helps make the defrost faster. If in doubt, get out the owner's manual on a rainy day and bone up on its operation.

 

Pewter C5, it's just like they say that you should run your a/c in the winter months (remember?) 10-15 minutes a week to run the compressor, etc. It's the same thing with your heater core. I may be wrong but if you don't use your heater, the coolant inside the heater core will not circulate. Thus the coolant just sits in there and eventually it leads to heater core problems (i.e. leaks)...ask any mechanic.

 

I believe coolant flows through the heater core at all times.

When the heat is not needed air is diverted around it by the flaps in the heating ducts.

I'll look at my car when I get it back from the dealer to verify this.

Eric

 

Actually, what leads to heater core leaks is that it is made of the thinnest metal in the system. When the cooling system is neglected (not changed every year) it will cause problems here first.

Eric

 

the A/c works with defrost mode to dry up the air and make the window defrosting quicker and easier. I don't know if the heater uses the A/C on the windsheild also...I haven't ever used the heater alone as I don't like hot air blowing directly on me.

 

Nilla, understand. I don't care for hot air blowing on me either :D but there are times when the defrost mode will have to blow hot air on the windshield (e.g. when it rains and the windshield begins to fog up). I will never experience that since I don't drive mine on rainy days...however in the event I am caught in a rainstorm I prefer to use some "hot air" blowing on the windshied to keep it clear. I guess I just hit the "Defrost" button, crank up the temp to 90 degrees and that should do the trick. I re-read the manual last night and the instructions on using this automatic climate control system are for the "birds." They are not very clear. All I wanted when I ordered the 1SB package were the fog lamps...but GM through in the darn auto climate system, sports seats, etc. Give me the old "manual" control system and do away with all these "bells and whistles." If a sensor (i.e. the outside temp sensor located under the front bumper) goes awry...you're in trouble.