A couple of weeks ago the indicator lights on the Heating/Cooling control panel of my 99 Accord started flashing, I had my AC on and noticed that every time the lights came on the AC would work and every time the lights when off the AC wouldn't work. I was unable to change the settings (vent through top/bottom/etc or turn AC on/off) while the indicator lights were off. After turning the car off and back on, I noticed that none of the status lights on the Heating/Cooling control panel came on. The vent fan is working perfectly fine (level 1, 2, 3, and 4) but it only vents through the top (last setting set before lights went out) also the AC was working perfect before the Heating/Cooling control panel lights went out. I'm thinking the problem is with the panel (electrical at least) but don't know how to diagnose that, the check engine light does not come on. I've checked all fuses and all looks good. Don't really now how to check relays. Any idea? I've never had a problem with this before. This was two weeks ago.

 

I've got the same problem but do not know how to identify the relay and test it.

 

Any little advice would help. I live in Ft Worth, Tx and it has been over 100 degrees lately. I don't know how much longer I can stand driving 30 minutes to work each way in this temperature. I hate taking it to the dealer ... I don't have one million dollars to spend.

 

I would check the dimmer switch first on the left side of the steering wheel.

 

Have the Battery and charging system checked (Autozone will do it free of charge). The same thing was happening to my 03 Accord, and since I have a helm manual I checked through the diagnostics MICU, and the first thing to check was the battery/charging system. It tured out being a simple weak battery (spent $45 at sams and everything is fine since then). I also noticed that the shift position indicators on the dash would not light up when this happened (the P for park would light, but none of the others would). All caused by the weak battery. I know it's hard to believe, but it's true.

 

I had the battery checked and still nothing. As for the dimmer switch I don't see how that would make the AC stop working.

I found this Post on another section I need to check it out. I'll keep you posted.

https://honda-tech.com/zerothread/2071101

 

Im sure by now you've found this out, but I joined just to provide an answer. I had searched these boards,google and several other places and this is the most spot on description of the same problem I had with a 1998 Accord EX. But alias, no follow up answer.

I also tried changing the battery (i needed to do that anyway) and it did nothing. As it turns out, the problem is electrical and its with the "heater control panel". It could be shorting out or there may be an open circuit, but the unit is one piece that has to be replaced. In my case the problem was intermittent. It would do it a few times and then not do it again for 8 months.





Just a few key words to help anyone looking for this. I had a hellava time searching thru post with ac and A/C.

"AC light cut off"
A/C light cut off
AC light shorting out
A/C light short

 

uhm you can remove and resolder that control board yourself, prolly save yourself a shiet load of $$$

 

i have exactly the same problem. i would love to resolder things myself but i'm not equipped to identify exactly what needs resoldering. i removed the panel and inspected the circuit board inside and everything seems okay. but then, i have no idea how things ought to look.

i do, however, know that the leds come on when i reattach the temperature control wiring to the panel. when i reassembled everything it was okay for about 45 seconds. then it shut off. i've found that occasionally whacking it will make everything light up again (and re-engage the temperature control system) but that's not what i'd call a long-term or elegant solution.

one question, though: i've got the control panel pictured above, but i was wondering if i could use the digital type to replace/upgrade?

 

1999 accord LX. First ac light on/off would occasionally work or work then strop working down the road. Then (year or so of this) the lights started with a faint blinking and ac would not come on (compressor would not kick in). Finally, everything stopped working. Went to threads and saw the "jumper" around the voltage regulator but also just replace the ac contoller. Found a nice / used on on ebay for $85 (july 2020) and plugged it in. Bummer, nothing worked on this one either. So, went to the thread for jumping the board and son of a gun, worked beautifully. Can't believe someone figured out this fix, but it works.
Don't bother looking at the 'condenser fan' relay. That ain't it. of course, check the 7.5A fuse on the driver side, but most likely it's just this dang control board jumper.

 

Is there a thread on here about that jumper around the voltage regulator? I don't have trouble with mine now but would like to know about the workaround for reference.

 

I am not sure if the detailed info. ever got posted on H-T.

IIRC, somebody on Drive Accord found the cause and fix years ago; and posted it (refer to post #13): https://www.driveaccord.net/threads/...7/#post-913553

 

Thanks - that's what I was looking for and saved the post in a document.

There was a similar fix for the clock not working in my former Subaru Forester. That involved re-soldering a surface mount resistor. Surface mount components can be kind of tricky, it's better to use a small soldering iron tip.