Ghost Ryder

I have a 12 CTT with 4 zone climate control

The rear climate control seems to have a mind of its own. It doesn't seem to work for the first 5 minutes after I start the car. The lights and control are on, and it respond to the button presses, but I do not get any air (hot or cold) until about 5 mins into my drive. Is this normal?

Also after it start working, every so often the fan would surge for about 5 seconds, is this normal?

Thanks.

bweSteve

I also have a '12 CTT with 4-zone, and you are correct, that is not how mine behaves. That does not seem normal.

Without fail, and even if I have the "mono" button depressed from my drivers seat (which demands that the 2 rear zones follow suit to the temp & air-speed settings that I have for my master driver seat zone),.. when someone presses any button in the rear control panel for either rear zone, it over-rides the master (therefore the "mono" button light goes out), and they can control everything to their preference from the rear seats. AND, most importantly each of those control buttons in the back (temp & fan-speed) will actuate immediately. There is no delay as you describe. Nor is there any surging.

The surging makes it sound as though you have a wire shorting out somewhere.

Have you ever had any wet floor carpet issues in the past? Clogged drains maybe? just thinking out loud that maybe your wiring has been corrupted. Do you park it outside or in a garage?

As a side-note, even tho I park in my garage 100% of the time, I am maniacal about not letting any debris get down into the two front lower corners of the windshield (thus washing down into front fenders & clogging up the drain plugs).

=Steve

Ghost Ryder

It's pretty bothersome, I get no airflow in the back for the first 3-5 mins even though it register all my button presses. After that it works fine but I get surges for a few seconds every so often. I would bring it in, but it's out of warranty and I'm sure it'll be a few thousand to fix. The front works fine.

CarGuyNVA

Yeah, that doesn't sound right. My 4-zone system responds the same way Steve described his above.

Maybe it's a temp/humidity sensor issue? I recently had a new instrument cluster installed and the tech forgot to connect one of the interior cabin temp sensors on the dash and it caused abnormal behavior from the entire HVAC system, as well as affecting operation of things like the seat heaters too. When they reconnected it everything went back to normal instantly. Just a thought, maybe a bad sensor in your case? I'm not sure how many interior sensors there are, or if there are separate ones for the rear system on the 4-zone cars like ours, but maybe worth checking in to.

deilenberger

We're guessing here. With a tool like the iCarScan you can watch what's happening with the system and test components by activating them. My WAG would be the rear blower isn't working correctly, but without testing it's operation, I wouldn't spend a dime trying to fix it based on a guess.

Ghost Ryder

can icarscan activate the blower or other systems?

deilenberger

Yes. It can activate all the HVAC components. Very useful for troubleshooting. It also has a routine to recalibrate all the stepper motors that control the flaps that mix and direct air. This can make a big performance difference if they've lost the count sync (meaning the HVAC controller doesn't actually know what position the flaps are in.)

Very useful tool.