1986-1987 Hatchback LXI dash wiring harness questions

[Nate Bannon]

Alright I tried searching on the forum and found a little bit of stuff but no clear answer to what I'm trying to solve in particular. This all starts out with a dash swap. So I own a 1987 Honda Accord LXI hatchback 5 spd and the dash on this thing was trashed. In short I pulled an dash from a 1989 Honda Accord LX sedan auto. I had assumed that everything would be the same considering outward appearance wise they were identical. So my shop wound up doing the swap and not only did they find that the vent channels are a little different but that the climate control blend door was not working correctly. So I did some researching on the forums and found out that even though the push button controls on the 86-87 and the 88-89 are visually identical they are actually different part number. I imagine this has to do with a possible revision to the HVAC system that took place. So I went and grabbed my old push button control from the previous dash and the doors work but the control don't light up anymore! Now I'm freaked out because I'm terrified I put a whole new dash in my car and paid for it whilst simultaneously putting an incompatible harness behind it that I will now have to get the dash removed again to replace! So here's where my questions come in.

Is my diagnosis even any bit accurate as far as year range effecting the climate control and having to replace the entire harness again?

Do any of the other factors like LX vs LXI, 4 vs 3 door, or auto vs 5spd transmission effect anything?

Has anybody ever had to deal with anything like this before?

What harness will work in my car?

[conozo]

This is the first time I've heard of a difference between the climate control between years but I'm up to learn something new.

I would first make sure you dont have any blown fuses that may have popped during the install. Also make sure you have all the grounds under the dash connected, there is one specifically behind the clock that can easily be forgotten. The shop manual has an image of the location of all the grounds and i believe you can see them all without taking the dash out.

2nd i would take a look at the 1986-87 and 1988-89 shop manual electrical section to see if its any different there. PM me your email address and i can send you both manuals.

[ShiRen]

In the 89 there should be some extra levers and such, in the center vents and levers by your right knee. Not sure why you couldnt use the 87 climate control unit though and leave the extra stuff unplugged. Isnt your blend door just cable operated? I didnt think where where really any electronics
I know there are several different climate control units, ones that are totally push button operated and some that are even automatic, but the majority that I have seen are cable operated. With no pictures or anything its hard to tell what kind of predicament you are in.

[Nate Bannon]

[Nate Bannon]

Pictures make things easier to understand for sure. Unfortunately my mechanic is working on the car so I don't have any up close and personal what's going on outside of what I figured out at the junkyard. My understanding in another post a guy basically just said that you got a dashboard out of an 89 and he used to push button controls in his 86 and the blend door did not work correctly so he just put his normal push button controls back in. The difference between what me and him did is that he kept his original harness I use the harness that was in the junkyard dash. This is where I believe my problem started somewhere along the lines most likely during the year range revision they changed something electronically in the climate control. He even said that when he went Honda he asked if there were different part numbers for the push button controls between 86 and 89 there are. Does that needs me to believe that the harnesses are different. My mechanic also just told me that ACS have different requirements depending on whether your car's fuel injection or carbureted. So that could also be a factor as well. Right now I'm hoping that if I get the master shop manual from Honda if it has all the diagrams for the wiring maybe it will show differences that I'm looking for.

[Nate Bannon]

This is the first time I've heard of a difference between the climate control between years but I'm up to learn something new.

I would first make sure you dont have any blown fuses that may have popped during the install. Also make sure you have all the grounds under the dash connected, there is one specifically behind the clock that can easily be forgotten. The shop manual has an image of the location of all the grounds and i believe you can see them all without taking the dash out.

2nd i would take a look at the 1986-87 and 1988-89 shop manual electrical section to see if its any different there. PM me your email address and i can send you both manuals.

Hi thank you for the reply. I went in and talked with the mechanics t mechanic today saying no progress. I got a harness out of a LX sedan manual but he warned me that technically carbureted cars have different requirements for the AC to run properly. So he said that that harness could even be wrong. I get that most people probably never had this issue because they would have kept their original harness. Starting to think that I'm probably just going to need to track one down for my specific car. But I'd be more than happy to get the manual from you because my mechanic is actually asking for it to try and see if we could maybe troubleshoot the current harness pinouts and nail down if there is a difference between things like carbureted and fuel injection or even number of doors and transmission.

[ShiRen]

So if one or the other cars had the fully electronic controls for the vents then yeah youd need the fully electronic controls for the vents to use that, and on the flip side, you would need the cable actuator to use the cable controls for the vents. However, the hvac system might be very similar and its possible that the electronic motor can be taken off and a cable put on if your car was the one with the electric vents.
As for the ac, yes the carbed cars dont have anything to control the ac besides turning it off and on, the fuel injected cars can monitor the ac pressure and turn the fan off and I think regulate the clutch duty cycle, but I dont know if that has anything to do with the dash harness.