2005 Sebring A/C - Electrical Problem?
 

A couple of months ago my A/C and environmental control panel started to act funny, and only work intermittently. When it worked it worked, when it didn't all I had was the dashboard defog blower, no control over temp, and unable to use the electric rear window heater. Finally it got to a point that I noticed it only worked when I parked my car at the end of a drive. Funny I thought...So I started putting my car in park at red lights and stop signs, yet the system would not work.

Today I determined that the reason the system would work when I was about to get out of the car after a drive, because I turned off the headlights. I tested it out today, and low and behold, the A/C and environmental control panel works fine, with the headlights off. As soon as I put them back on, the system powers down. So this leads me to believe I have an electrical problem.

I had my battery tested today. 12.7 volts static, 12.6 volts engine running. Alternator is good.

I am thinking what is happening is with a low volt battery, the alternator is compensating, and eventually load shedding. Would putting in a new battery solve this problem? Any suggestions?

Thanks in advance.

You probably will have a better chance of fixing the control head problem by replacing the control head. It's a fairly common part, having been used on all non-ATC Sebring sedans and convertibles and all Dodge Stratus sedans from 2001 to 2006. The part comes up on eBay occasionally. Or you can cruise your local junkyards.
Removal is easy. Pull the bezel surrounding the control from the bottom using your fingers until the bottom pops loose. With a plastic trim tool or a wooden paint stirrer, pry off the bezel, reach behind and unplug the wires.
Going to defroster operation is the default failure mode when the computer detects some failure in the control head. In these cars, the controls on the dash are only there to tell the computer what you want to do. The body computer actually sets the heater to do what the controls say.