belairbrian

99 Accord EX Sedan

manual Controls

A while back I had to add the jumper wire inside the control to get it working.

Now the green light over the dash vent button does not work. Just went out a couple of days ago. Everything else on the control works, all other mode lights, back lights just not the one green light.

Anyone know if these can be changed? If so a bulb part number?

holmesnmanny

Common issue. It needs to be resoldered. Google it.

belairbrian

To be clear this is not the issue of the control panel not working. Every button on the panel works properly, the car responds to each button.

The issue is the led indicators above the dash vent button and the recirculate button. When either is pressed the air flow doors move as designed but the LED's do not come on. I resoldered the connections and even swapped the diodes with known good ones from another control panel. Also verified continuity for the ground side of all diodes and for the bad diodes back to there test points.

Since the FSM doesn't have the internal schematics for the panel I've run out of things to try.

tech8

The mode indicators are LEDs. Either there is an open in the circuit (solder joint, resistor, etc.) and/or the LED somehow got blown out.

belairbrian

As I had previously posted I had checked the diodes both on board, removed and using a known spare, they aren't the problem. So obviously it was a circuit path. Since I couldn't find a schematic for the board, I went ahead and mapped this section.

What I found were some bad through board vias. Rather than repair a bunch of vias I decided to jumper the circuit paths. I now have 2 fully functioning boards.

Essentially there are 8 resistors in series with the light emitting diodes the circuit paths transition from the rear of the board to the front then back to the rear.

I took some pics and labeled them in case anyone wants to avoid replacing the panel and just fix theirs. I still need to clean some excess flux from some joints. The only hard part is when attaching the wires at the resistors you have to make sure the wire doesn't touch a neighboring resistor.

As for wire I just stripped some wire from a piece of cat 5E I had lying around. As it is solid it makes better jumpers than stranded.

One of the boards had already been repaired for the unable to change modes/panel not responsive issue (that is the blue jumper)

Board showing resistor bank and blue jumper for the no response problem


Close up of the resistors labeled with the LED and functions. Before the repair for clarity



here is the other board with 3 repair jumpers installed

8888

I did a search before posting a new thread and this may be the answer but I'm not 100% sure.

My car is a 1998 Accord DX base model (crank windows and manual locks) and the base model "two dial" HVAC controls are not working properly.

When I saw not working properly, I mean that the rotary dial control changes fan speed properly and the heat/cool rotary dial works, but the button LED's above the various "directional" modes (floor/dash/defrost etc) do not always work. Neither do the lower buttons for the recirc/AC etc). I tested all this stuff when I test drove the car and they all were fine, it was probably in the mid 70's when I bought it, much warmer back then. The car sat for a few days outside before I drove it home and the directional LED's did not work when i started out, but started working halfway home.

The car sat for a few weeks in the garage after I drove it home until I drove it again tonight, it's been cold during that time and cold tonight. Directional LED's weren't working when I started out, so I decided to press firmly on the button for floor heat to see if I could get it to light up. It did light briefly and went out, I had heat from the floor vents. I tried the button for the dash and it lit briefly and I heard a groaning noise while it was lit and warm air came from the dash vents. I pressed the floor heat and got the light while the groaning noise was going on and got my floor heat back.

I did Google as recommended above and did not see exactly this situation.

Is this situation what the blue jumper above is designed to address? Please let me know.

The other thing is that there is no backlighting on the AC panel or the rotary dial for the fan, weak light on the temperature rotary gauge.

EDIT - it has an aftermarket stereo rather than the OEM, if that matters. Some references I see on the web make reference to the radio and HVAC lights seem to be affected together.

Thanks in advance.

Joe

holmesnmanny

Instead of doing what that guy did, take your board to someone that specializes in electronics and knows how to properly solder and pay them to resolder the board.

user456101

Actually, it is much quicker and really cheap to go to a junkyard and get a whole new controller and replace the whole thing. There are tons of these cars at my local junkyard (over 40).

8888

This is what I ended up doing, but it wasn't as straightforward as I thought. Most of them already had the controllers pulled but I was lucky enough to find a 2000 that just hit the yard and had a really nice, unfaded controller. Looked like it had been recently detailed as well, I took the clock/hazard switch assembly too, because mine did not light up and the hazard button was faded.

When I got home, I pulled the controller out of mine (1998) and the replacement wouldn't fit in the dash bezel. Upon further review, my old unit was designed for a bezel with circular cutouts for the dials and a rectangle in the middle for the buttons etc. What I pulled required a single large cutout for the dials and buttons.

So I went back to the yard to get the bezel from the same car.

I always plug everything in as a test before buttoning it up so I plugged in the hazard light switch and it lit everything on the cluster up like an Xmas tree, almost like a diagnostic plug. I plugged in the old hazard switch and it worked just fine. Hmmm. There was a small white adapter on the back of the original hazard switch, I originally thought I could transplant it to the new switch but it did not fit.

I figured I would just put the old hazard switch in the new clock assembly but it was loose to the opening in the clock assembly. Upon even further review, I noticed that the clock assembly from the 2000 was larger so the old clock assembly would not fit the hole in the bezel. So I was stuck with the old hazard switch to avoid the Xmas tree cluster with the new clock/HVAC controller/bezel. I ended up wrapping a bit of electrical tape around the hazard switch to make it tight to the clock assembly and that's what is in the car.

Everything seems to work okay so I guess I'm good to go. I assume the 2000 was a DX like mine because it had crank windows, I just found it funny that there were so many differences between the 2000 and my 1998 and thought I would post this so others were aware of it.

VTguy

Great instructions. Very helpful. I am running into an issue that I haven't seen mentioned yet, and I am wondering if anyone is familiar with the circuit board to help navigate the problem.

I have implemented the jumper from the capacitor to the regulator which brought the board back to life. However, the buttons that control the air flow direction light up and change when you press the associated buttons, but the actual air flow direction does not change. Now it is stuck on the dash position regardless of what the light shows. Everything else in the climate control works fine (AC, recirculation, defrost, warm/cool ****). I know the motor that control the air flow direction works because I have an older board which can change those positions, but the board has other problems. Any thoughts what could be the issue? How can I indentify the break in the circuit or the broken component. My car is a 2000 Honda Accord LX. Thanks.