January 22, 2007

Taillamp Combination Rewired

For reasons unknown to me, the North American spec Fit have their turn signal on the inside of the taillamp, and the reverse lamps on the outside. I don't know why this bugs me so much, but it does. So I finally got around to reversing the two lights around last night.

Let me just say that unless this really irritates you, don't bother with it. It's probably more hassle than it's worth. I had originally thought it would be a simple case of switching the bulb holders over. Unfortunately, that turns out not to be the case, as the tabs on the bulb holders, and the corresponding cutouts on the back of the taillamp, were different between the turn signal and reverse lamps.

So then just swap the bulbs between the clear and the amber and switch the connectors in the back right? Wrong. the connectors for the turn signal and reverse lamp bulb holders are different, and not compatible with each other. And also, the clear reverse bulb (7440) and the turn signal bulb (7440A) are actually slightly different with the glass tabs on the clear 7440 bulb being slightly bigger. This prevents the 7440 (reverse) bulb from going into the 7440A (turn signal) bulb holder.

Ok, now we're getting creative. What if I swapped the pins in the harnesses so that the turn signal wires are going to the reverse lamp bulb holder, and vice versa. Well, that didn't work either since the pins are actually different for each harness, and they won't seat properly in each other's harness (staying loose, able to move back and forth within the harness). Plus, even if that worked, the bulbs still can't swap easily as mentioned above.

So, what would work? Well, I see three ways of doing this.

Method 1. Go behind the driver side rear taillamp rear cover, and you should see a 10-pin harness. That's the floor wire harness from the car to the rest of the taillamps. Disconnect the harness, open it up, and swap a few wires around. Namely the left turn signal wire (green/red) with the left reverse lamp wire (green/black), and the right turn signal wire (green/yellow) with the right reverse lamp wire (green/black). Grounds don't matter since all of these bulbs go to ground themselves. Do this only on one side of the harness. Swapping pins here works because it's all from one connector harness, so the pins are the same. Now, take the turn signal (7440A) bulb holder, remove the connector pins inside, and file down the plastic ridge on both the top and bottom that is causing the 7440 bulb not to slide in. (you'll see which ridge is the problem when you try to put the bulb in).

This method is fairly clean, but the harness is rather difficult to work on unless you remove the entire interior trim panel and remove a few retaining clips. Even then, the removal of the pins might give many a lot of trouble if they're not used to working with such things. Also, the turn signals are a thicker gauge wire than the reverse lamps. They should both be drawing the same current, but because the turn signal turns on and off constantly, the thicker gauge is preferred. By swapping the pins at the 10-pin harness, the rest of the circuit for the turn signals wll be running at the thinner gauge wires. It shouldn't cause any problems, but it's just something to keep in mind.

Method 2. Cut the wires at the bulb holder harnesses and swap harnesses between the turn signal and reverse lamp wires. Then, you'll have to take the 7440A bulb holder, remove the metal connector pins inside, and file down the plastic ridges on the top and bottom that is preventing the 7440 bulb from going in all the way. This is the method I choose as it was easiest for me to work on. I didn't want to remove the entire inside panel in the back to loosen the 10-pin harness mentioned in method 1. And also of note is that with method 1, some wires may still need to be extended to reach their new location (namely the driver side reverse lamp)

Also note, if there is a remote possibility of you swapping out your taillamp for any other types; JDM LED, Altezza, 3D, anything, Do not do this mod with method 1 or method 2, or else you'll have to swap the connectors back again when you change taillamps.

Method 3. (recommended) This is the method I would recommend, provided all the wires will reach without extending (please double check, especially driver side reverse lamp). However, this method might cost you money. Go to Honda parts and order the bulb holders for the reverse bulb (p/n 33515-SJD-003 USD$5.47 retail) and the turn signal bulb (p/n 33514-SAA-003, USD$6.47 retail). These come in pairs. After you get them, use a file to reshape and/or remove tabs so they they will fit in their new locations. Try not to completely remove more than one tab or else the bulb holder may not sit in the taillamp securely. This is probably the cleanest and easiest method for those who would rather not work with the electrical system, and easily reversible (just replace modified bulb holders with stock ones), and keeps the connectors proper for future taillamp upgrades (JDM LED, etc).

Alternately, you can just file down your stock bulb holders to fit. Technically it will probably still be reversible since your tabs are now smaller if anything. But they might not be as secure as before.

As I mentioned before in my blog, patience is not one of my virtues. Since I had already started the project last night (Sunday), and even took the pins out of the bulb connectors, I decided to finish the job then instead of waiting 'til the next chance te dealers open and I can go buy some bulb holders. Well, that plus on my car it really looked like I'd have to extend wires on the driver side anyway. So I employed method #2. Everything is done cleanly, but hey, it's always better if you don't have to cut wires, and is totally reversible easily and without a trace, like in method #3. Oh well. It works. And now my turn signal and reverse lamps are in their "proper" places. So I'm happy.

1 comment:

lanakano said...

Thank you so much for the very good DIY guide "Taillamp Combination Rewired." I followed your method # 3 last night and wanted to comment on how easy it was to do.

Method 3 is just a simple action of moving the turn signal bulb socket over to where the backup light bulb socket is and vice versa.

In addition, I found that the socket to taillamp housing asy patern doesn't have to match up perfectly. One tab can be way off as long as you can angle it in first and seat it in the track then one can twist the socket left or right to align the other tabs.

Last but not least, the seating of all of the tabs of the bulb socket onto the taillamp asy is easy because you can look through the taillamp lens to see what is going on.

Thanks again for a great DIY. I plan to try the fog light DIY this weekend.

FitFreak.Net User ID: lanakano