2014 CX5 Tour 2.5L

Battery had been weak for several days so we bought a replacement. GF waited in car with engine running (in case Walmart didn’t have the battery in stock). AC was working fine when I came out with the new battery.

Shut off engine and replaced battery, which took a total of about 15 minutes.

I always expect to do minor things like reset clocks after a battery disconnect, but this time the AC blower fan stopped working. Dash fan-speed display works normally in concert with the speed-control ****, and compressor is also working because cold air gets forced through when the car is traveling at speed.

Two weeks ago I disconnected the battery to clean the terminals, and had no unusual issues upon reconnecting.

Anyone see this before?

 

Rather than deleting this thread, I’ll leave it up in case it may help someone in the future.

Thinking about the difference in my recent battery disconnect for cleaning, versus today’s removal for replacement, I decided that the main difference was the length of time that power was removed. Replacing the battery took only 15 minutes, but my cleaning was over a half hour.

Electronic systems vary in the amount of time they are able to store charge, as well as the actual voltage at which they “go dark“. I reasoned that I had possibly caused some type of random partial reset by reconnecting power when some circuits were fully dead with others still energized.

So I disconnected the battery again, this time for about 45 minutes. I also depressed the brake pedal several times during this interval, to drain any stored charge that might be present in parallel capacitors.

Upon battery reconnect, my A/C fan is working normally.