HVAC(manual) unit will not function; possible broken solder joint fix?

I've noticed at times my HVAC control unit(manual one), will not function aside from the fan speed knob. The buttons and air temp knob light up but their indicator lights do not. Pressing the A/C, Recirc, Rear Defrost or any of the air buttons does nothing.

After tapping on it a few times or simply just driving on and giving it a couple minutes the indicator lights will come on and will work fine for the rest of the time.

On mine this started happening after we had a few extremely cold days in here during the begging of the year.

I've already checked the wiring and all is intact; I took a peek at the pcb board of the control unit as well but with my eyes I did not see any cracked solder joints

Anyone had this issue before and fixed it(without buying another unit)? find out which joint was cracked and needed some fresh solder?

I did have this issue. No power at the voltage regulator. Ran a wire there and also had to run a wire to the recirculate bulb as that was intermittent as well. I can take a picture tomorrow.

Better yet...

http://petervieth.com/2012/01/29/heater-and-ac-controls-not-working-on-a-99-honda-accord/

UPDATE: This link is now broken. Scroll down to my later post in this thread to see the image of the wire run I made from 12v supply on the board to the voltage regulator.

UPDATE: The link is no longer broken!

james'99 said:

Better yet...
http://www.petervieth.com/2012/01/29/heater-and-ac-controls-not-working-on-a-99-honda-accord/

Click to expand...

OMG! Great find, I've been having the same issue since buying my car.

I've been meaning to get a soldering iron also but could never justify buying one but now, Raidoshack here i come (when i get paid) lol.

Haha! Awesome! Let me know how it works out for you!

james'99 said:

Haha! Awesome! Let me know how it works out for you!

Click to expand...

[UPDATE!!!!] So i did the fix and so far so good it was pretty simple and that's coming from someone with probably 30 minutes worth of soldering experience.

thanks again for the post. James'99

I'll update if anything happens.

Not a problem. Glad to be of assistance!

I gotta bump this thread, the link won't work for me.


Also, it's about to be summer here in SoFla. That AC will be clutch.

Unfortunate that the guy took down his site. I am on vacation so I cannot demonstrate verifying the failure with a multimeter but I will take a picture of my repair. You're gonna need to run a wire from the 12v power supply on the board to the 5v voltage regulator. I will take a picture of my repair momentarily.

Okay, here is where the wire runs...