1998 Export taillight wiring HELP

FivepointSlow · Mar 10, 2019

So I remade wiring harness' for both taillights to use the amber turn signals as they should work for export Mustangs.

The inherent problem with this is US Mustangs use the same bulbs for brakes and signals, and I am now trying to use a separate bulb for signals.

From what I have read, all that I need to do is disconnect a wire next to the steering column that is suppose to be green, I believe its technical name is the brake signal interrupt, it basically overrides the brake signal when the turn signal is active.

I found a video on a New Edge harness that shows the wire on the bottom corner of the harness. On my car I located the same harness, but the dark green wire is in a different position than what I saw on the New Edge harness.

I want to be sure I am cutting the correct wire, but can't seem to find a wiring diagram on that harness as I do not know really what to look up, I don't know what the harness goes to.

Does anyone happen to know what exact wire needs to be cut? Has anyone done this on a 98 before?

I know theres a very detailed write up on this exact modification but the link is dead and I can't find any other relevant detailed write ups

Wood's 5.0 · Mar 13, 2019

Man, I remember doing mine back around 2001 and it was a BITCH! I have a '95 and I think the '98 is similar as far as number of bulbs, etc. I think just the lens in the housing is different but not 100% sure. As I'm sure you well know, '98's have a few MY-only differences from the earlier SN95's that make them kind of unique. I couldn't figure out how to do this mod so had a friend of mine, a Senior Master Tech at the Ford dealer do it and it gave him a fit, too. Had to RUN a wire from the multi-function switch on the steering column back to the tail lights and jump connectors on the tail light housing from bulb to bulb, to make them work. Oh, and the turn signals hyper-flash to this day because of eliminating a bulb in each housing or something he said had to be done. Hoping the Ford relay from Diode Dynamics remedies the hyper-flash but have not installed it as of yet. That's probably gonna be a bitch, too. They look cool and all but IDK if I would do it again without the factory harness for an export Mustang. Ya know, even at the MCA National Shows, the export tail light mod is something very few people even notice on mine unless they are REALLY into the SN95's. Way more people catch the export fender flares than the amber turn signals. Wish I was more help. Good luck.

ttocs · Mar 13, 2019

I think that is the 2nd time this month I have heard someone make it out as though its almost impossible. I am not sure what the problem is myself but then I have also never considered spending what they want for lights.

g36 monkey · Mar 13, 2019

There used to be tons of writeups on this, what happened? I need to make a couple harnesses for when I put the Cobra lights in.

FivepointSlow · Mar 13, 2019

ttocs said:
I think that is the 2nd time this month I have heard someone make it out as though its almost impossible. I am not sure what the problem is myself but then I have also never considered spending what they want for lights.

Definetly not impossible. Actually super straight forward. My only hiccup is identifying which wire needs to be disconnected. If I really need to I could run a signal wire tapping into the front signals and run them back to the trunk but disconnecting the brake signal interrupt would be much much easier if I could just know for sure which wire it is.

g36 monkey said:
There used to be tons of writeups on this, what happened? I need to make a couple harnesses for when I put the Cobra lights in.

I know I've found a dozen links to write ups and im sure they're all beautifully detailed write ups but theyre all dead and those that arent dead links arent detailed enough or arent for 96-98 years... lol just my luck.

I messaged TKORESTO from YouTube on his personal Instagram because hes done a bunch of work like this and he said it should be that green wire regardless of which pin in the harness its located, as long as it's the same green wire that the third brake light uses it should be the right one so I guess I'm gonna try that.

g36 monkey · Mar 13, 2019

If you don't have it sorted out soon I will go ahead and do mine up sooner than I planned to help you out. I'll make sure to do a good writeup.

ttocs · Mar 13, 2019

I am not sure why wiring needs to be ran. All the wires are back there that should be needed. A meter and 10 mins and I could figure it out. I bet a little time and you could as well. You need to identify 4 wires, the turn signal, the parking light, the brake and the ground. After that it should only be a matter of tapping the turn signal to the new bulb.

g36 monkey · Mar 13, 2019

ttocs said:
I am not sure why wiring needs to be ran. All the wires are back there that should be needed. A meter and 10 mins and I could figure it out. I bet a little time and you could as well. You need to identify 4 wires, the turn signal, the parking light, the brake and the ground. After that it should only be a matter of tapping the turn signal to the new bulb.

That's pretty much all it is.

ttocs · Mar 13, 2019

you really should only need to identify 2 wires, the turn signal and the ground, but there are 2 other wires as well that I mentioned above. The parking lights are commonly a brown wire to take one out of the mix that you do not need. Get a meter/test light and turn your turn signal on and start checking the wires going to the bulbs until you find one pulsing 12v-0v as the bulb turns on/off. Cut the wire going to the bulb(leave a few inches in case you need/decide to reconnect it) tap the ground right next to it and run that down to the new turn signal bulb in the new spot

FivepointSlow · Mar 14, 2019

ttocs said:
you really should only need to identify 2 wires, the turn signal and the ground, but there are 2 other wires as well that I mentioned above. The parking lights are commonly a brown wire to take one out of the mix that you do not need. Get a meter/test light and turn your turn signal on and start checking the wires going to the bulbs until you find one pulsing 12v-0v as the bulb turns on/off. Cut the wire going to the bulb(leave a few inches in case you need/decide to reconnect it) tap the ground right next to it and run that down to the new turn signal bulb in the new spot

The trunk area of the wiring is already done. That's the easy part.

The issue with this modification is there is no dedicated turn signal wiring in a non-export mustangs trunk. The turn signal and brake are shared over the same wire.

The brake lights are wired into the third brake light wiring for a brake signal only
The amber turn signal is wired to the old brake/turn signal wire, and just needs to be converted to a turn signal only wire.
By disconnected a wire under the steering column up front its suppose to essentially kill the brake signal interrupt function thus rendering the brake signal over that wire non-functional.

The purpose is to get the red lights to function as brakes/running lights only (in their respective major/minor filaments), and the amber as turn signal only. Currently as is, the turn signals function as intended, but the brake signal is feeding back through what I need to be the turn signal only wiring and powering the turn signal when brakes are applied as shown here:

ttocs · Mar 14, 2019

ah, I see now. With the 3rd brake light not being associated with the turn signal it seems like there should be a way.

ProjectGunshū · Mar 14, 2019

I'm in the process of figuring out the wiring for export-style taillights as well, so I'll definitely be keeping an eye out to see what you find out. Trying to not spend the amount of money my car is worth for a set of taillights.

FivepointSlow · Mar 14, 2019

I got it figured out, I am going to jam out a new write up now so no one has to go through what I did lol. I'll reply here with a link to it when its done.
Thank you guys for your thoughts and advice.