A/C not working, light blinking on control module

JAMIE MITCHELL

MEMBER
1999 HONDA ACCORD
2WD
AUTOMATIC
115,000 MILES

My temperature control panel sometimes blinks when I push the button for A/C. If it is blinking, the blower works, but the A/C does not. However, if it becomes solid, the A/C works like a champ. I also just realized that they become solid if I turn on my headlights. And the A/C begins working again. I can hear the compressor kick on as soon as I turn the headlights on. What in the heck causes this?

Tuesday, July 6th, 2021 AT 5:41 PM

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

The light blinking means there is either a code/fault with the module or the module is running a diagnostic routine. The fact that this stops when you turn the headlights on normally points to an issue with the module that when you turn the headlights on, it interrupts this issue and it starts functioning.

You have a OBD II car so I would start with checking for codes and see what is there.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

If there are no codes then more than likely the module needs replaced which is what I would do as you can find one from a salvage yard pretty easily for less then $100.00.

I attached the process below on how to change this. Please let us know if you have other questions or if you have codes. Thanks

Image (Click to make bigger)