mxw1

Hi,

I meant to say; Hvac Fails to Recirculation Mode, in the title.

I have a 2000 FRC with dual climate controls.
Recently the HVAC controls have started to fail into the Recirculation Mode after the ignition is turned off. It started a while back and only occasionally did this, but now it's just about every time.
Any ideas other than replace the HVAC head?
Mike

mxw1

Has anybody had this problem and found the fix?

Bill Curlee

SOMETHING to PONDER!

Most C5s that have Dual Zone have MEMORY FUNCTION. IF,, the memory is set to RECERC, it will go there every time!

Reset all the interior memory functions, (HVAC Settings, radio channels and volume, mirror position, seat position, Hud settings ect, ect) to something that you want them to return to and them press and hold MEM-1 & MEM-2 until the little MEM light BLINKS to memorize those settings.

When you unlock the car with the FOB, it will set all those things to you're personal settings.

OR

If you have a WEAK BATTERY and every time you CRANK the engine, the HIGH CURRENT starter causes the battery buss voltage to drop LOW (around 8-9 VDC) it will cause the BCM shut down loose ALl of those memory settings and cause the HVAC to DEFAULT to defrost and recerc mode..

Bill

mxw1

Thanks Bill.
It's a 2000 FRC and doesn't have any memory 1 and 2 key fob or buttons on the left door. I know what you are talking about, my 2003 did have memory functions.

It could be the battery spikes low on start-up. We use the car everyday, sounds like it cranks normal, but I'll clean the battery terminals and see if it happens less often.

Thanks for the input.

Mike

DetroitPlac

Interesting. I've noticed mine defaulting to recirc on every startup lately as well. In4upates

Bill Curlee

Recommend having the battery fully tested at one of the autoparts places.
Have them check for CCA, Reserve capacity and see what the output voltage does under heavy load.

Replace the battery if it can not support more than 10 VDC output under full load. Our modules SHUT DOWN and reset when the battery voltage drops low out of spec (like when you cold crank the engine).

Bill

3sACROWD

If the HVAC is set to auto mode and the interior is hot from sitting in the sun, the AC will default to recirculation mode to get the interior temp down as quickly as possible. Once the desired temp is achieved, it will switch out and bring in fresh air. The fan should be running at high speed as well.

DetroitPlac

Oh, wow...I didn't know it did that.

Mine is never on auto, though...I can't stand the fan always blasting. I think I'm going to try changing the battery. It's 8 years old, an dI deep cycled it a few times this spring getting the car running.