james'99
Well-Known Member
If you are experiencing issues with your manual climate controls where the controls are not working and no matter what button you press, no lights light up (Defrost, low vents, high vents, recirc, etc.) and only the fan speed knob works, the common failure seems to be a broken connection in the PCB between 12v supply and the voltage regulator for the step down to 5V.
I covered this repair at a high level in this thread.
http://www.6thgenaccord.com/forums/showthread.php?t=48606&highlight=HVAC
I found myself doing the repair on a second car so I decided it was time to share. This repair definitely applies to all 98-00 4 cylinder Accords with maybe the exception of DX Accords without A/C. It SHOULD apply to 98-02 Accord 4 cylinders with the minor exception I already stated and 98-02 Accord V6 LX editions with manual climate controls.
This takes a small amount of solder skill. Make sure you do the right wire run or you will find yourself having problems down the line.
I'd like to give credit where credit is due, but this original website seems to go up and down all the time but this is the original source from where I fixed my first one. I will now be doing a friend's.
http://petervieth.com/2012/01/29/heater-and-ac-controls-not-working-on-a-99-honda-accord/
Obviously to protect myself...
NOT RESPONSIBLE FOR DAMAGE DONE TO YOUR CAR FROM THIS DIY. *SHOULD YOU DECIDE TO DISCONNECT THE BATTERY BEFORE PERFORMING THIS PROCEDURE, YOU WILL NEED RADIO CODE*
First, you will need to remove the climate controls from your dash. I don't have pictures at the current time but get a phillips head screwdriver, a common screwdriver (flat-head), and a paper towel. Cover the end of the common screwdriver (flat-head) with the paper towel and pry beneath the clock. It will pop out. Pull it away disconnecting the harness for the hazard switch and clock. You will find a screw hidden there.
Next, place the car in neutral if you need the room to work and get the two screws on the bottom. At this point, the climate controls will pull away.
Two harnesses to disconnect here. Green on the climate control board and brown on the fan control. Pull it away.
Now...
Turn it over. Twist out fan control light bulb. Remove seven gold screws gently. (Screw locations dotted in red.) If you aren't gentle, you will break these already brittle studs and you will find your buttons not actually pushing from the front without all the screws. The remedy without replacing the plastic simply put is duck tape across the back from the top to bottom of the plastic appending the white plastic to the black.
Pull plastic away gently and remove the board.
Now here is the wire I used. I have no idea what its called but it works great in this application. I has some kind of coating as its insulation. It is single strand. I'm hoping xci or someone else will tell me but we will see. Haha!
I scraped about a 1/16 in of the insulation off on each end. Depending on the path of your run, and the type of wire you use, you will need different lengths. For my thin wire, I think it's about 5-5.5 in. This picture doesn't show it well but it gives an idea.
Solder point to point!
These pictures are clearer from the first time I did it on my car.
Place the board back in the white housing and put on the black cover. Take extra care reinstalling the screws. I recommend placing them in the hole and turn them counterclockwise with the screwdriver till you feel the screw "fall in" slightly. This will decrease the possibility of the studs breaking and hopefully the screw will take the same exact path in that it took on the way out. Remember, this isn't like metal.
At this point, plug in and test. If you are all good! Great! If not, you may want to check the continuity between the two points which you soldered the wire between and check for voltage there if you plug it into the car and turn the key to on. If there is no voltage at one of the two points, there is an issue. There should be 12v at the point on the "left" that you soldered. You are repairing the path to the voltage regulator, the "right" one. When I say left and right, look at the first picture of the finished product titled, "Solder point to point!"
I covered this repair at a high level in this thread.
http://www.6thgenaccord.com/forums/showthread.php?t=48606&highlight=HVAC
I found myself doing the repair on a second car so I decided it was time to share. This repair definitely applies to all 98-00 4 cylinder Accords with maybe the exception of DX Accords without A/C. It SHOULD apply to 98-02 Accord 4 cylinders with the minor exception I already stated and 98-02 Accord V6 LX editions with manual climate controls.
This takes a small amount of solder skill. Make sure you do the right wire run or you will find yourself having problems down the line.
I'd like to give credit where credit is due, but this original website seems to go up and down all the time but this is the original source from where I fixed my first one. I will now be doing a friend's.
http://petervieth.com/2012/01/29/heater-and-ac-controls-not-working-on-a-99-honda-accord/
Obviously to protect myself...
NOT RESPONSIBLE FOR DAMAGE DONE TO YOUR CAR FROM THIS DIY. *SHOULD YOU DECIDE TO DISCONNECT THE BATTERY BEFORE PERFORMING THIS PROCEDURE, YOU WILL NEED RADIO CODE*
First, you will need to remove the climate controls from your dash. I don't have pictures at the current time but get a phillips head screwdriver, a common screwdriver (flat-head), and a paper towel. Cover the end of the common screwdriver (flat-head) with the paper towel and pry beneath the clock. It will pop out. Pull it away disconnecting the harness for the hazard switch and clock. You will find a screw hidden there.
Next, place the car in neutral if you need the room to work and get the two screws on the bottom. At this point, the climate controls will pull away.
Two harnesses to disconnect here. Green on the climate control board and brown on the fan control. Pull it away.
Now...
Turn it over. Twist out fan control light bulb. Remove seven gold screws gently. (Screw locations dotted in red.) If you aren't gentle, you will break these already brittle studs and you will find your buttons not actually pushing from the front without all the screws. The remedy without replacing the plastic simply put is duck tape across the back from the top to bottom of the plastic appending the white plastic to the black.
Pull plastic away gently and remove the board.
Now here is the wire I used. I have no idea what its called but it works great in this application. I has some kind of coating as its insulation. It is single strand. I'm hoping xci or someone else will tell me but we will see. Haha!
I scraped about a 1/16 in of the insulation off on each end. Depending on the path of your run, and the type of wire you use, you will need different lengths. For my thin wire, I think it's about 5-5.5 in. This picture doesn't show it well but it gives an idea.
Solder point to point!
These pictures are clearer from the first time I did it on my car.
Place the board back in the white housing and put on the black cover. Take extra care reinstalling the screws. I recommend placing them in the hole and turn them counterclockwise with the screwdriver till you feel the screw "fall in" slightly. This will decrease the possibility of the studs breaking and hopefully the screw will take the same exact path in that it took on the way out. Remember, this isn't like metal.
At this point, plug in and test. If you are all good! Great! If not, you may want to check the continuity between the two points which you soldered the wire between and check for voltage there if you plug it into the car and turn the key to on. If there is no voltage at one of the two points, there is an issue. There should be 12v at the point on the "left" that you soldered. You are repairing the path to the voltage regulator, the "right" one. When I say left and right, look at the first picture of the finished product titled, "Solder point to point!"
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