When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Originally Posted by krburrell[img]images/buttons/viewpost.gif[/img]
Just to update this thread. I finally had a chance to install the middle tail light. The harness worked great. No codes and no other issues.
Hi krburrell, I also finally had a chance to install the middle light bar. Thanks for your help ... it all worked great. No codes and no other issues.
I purchased the Light Bar from online from Suncoast Porsche Parts & the pigtail plug from DeyTrade, then just sliced into the license plate wiring. Just love the look on my Guards Red 991.2 GTS! The old black trim between the taillights just didn't agree with the iconic styling of the 911 coupe ... some would think it is false advertising of a AWD GTS ... no worries for me as Porsche should have used the Light Bar on all models!
I've searched this and apparently it's not doable. Many have seen what it involves and they just weren't willing to take on the task. Also talks of having to to a complete rewire.
I do remember seeing something where an Asian guy had it done on his GTS but it wasn't in English and there were no details on how it was done. Just some photos.
I absolutely love the full light bar look. So damn nice, especially at night.
But I didn't want the all wheel drive, or spend the extra cash for the AWD GTS just for that light.
Sad that I actually considered it for that light alone.
I have discussed this in a prior thread. I even had my Porsche service department take off the rear bumper to see if they could figure out if it could be done. They say no but based on what I have seen, I am pretty confident it is doable. Two RL'ers have posted C2 GTSs (one in Asia and one in Europe) that have been modded from the grill to the light bar. My service department says that the entire light wiring harness would have to be changed to make it work and that splicing wires is not advisable. It is not a simple plug and play, unfortunately, because the C2 wiring harness does not have the extra plug for the light bar that the C4 GTSs have.
So I read the two previous posts about this mod and wanted to try this on my 2018 991.2 GTS that I was getting soon. I did not have the car yet so I ordered both rear bumper wire harnesses to compare them (each one is about $185). I got the C2 harness (P/N 9P1-971-174-D and the C4 harness (P/N 9P1-971-174-E) unfortunately I can confirm that this is not plug and play. The C2 harness has a connecting plug with 8 pins and the C4 harness has a connecting plug with 10 pins. The two extra pins go to the center tail light connection. There is also a third connection for the center tail light as well which I assume is for ground. The rest of the harnesses are exactly the same. When I have some extra time I will try to study the wiring diagrams and see if it is possible to splice the two connections into some other lights (e.g. license plate, tail lights) Not sure if this would work or cause some kind of error in the car. As you will read and hear, Porsche builds the wiring to match the cars and does not put in any extra wiring that is not needed.
OK I finally had some time over my holiday break to study this and have good news. This looks like an easy mod to perform once you take the rear bumper cover off. Looking at the wiring diagram I saw that the middle tail light actually has two lines and ground. One line is connected to the right tail light and the other is connected to the left tail light. Using the 4S harness I was able to determine the connector that plugs into the middle tail light (which is part number 4F0973703A). I also saw in the wiring diagram that the two license plate lights are connected together as a single circuit. I built a plug and play harness that connects into one of the license plate lights and feeds both lines of the middle tail light. I purchased both pieces to make the harness online. The licence plate harness came from an ebay kit to add LED lights and the other harness was a pre-made piece that had a 4F0973703A connector on it. I spliced these together to make this harness. I will go back and cleanup the harness with soldered connections and shrink sleeving to make it water proof then have the light installed on my car.
I checked the setup with the engine running to see if I got any errors and did not get anything. Also as a test I removed one licence plate light and did not get an error. I then I removed both licence plate lights and got an instant error as soon as I turned the key.
Here are the part numbers needed:
Middle Light: 991-631-465-02 5X light mounting nuts: 999-076-056-01 (no need to order, re-use what is on the car)
Middle tail light harness: 42831100-PT (from DeyTrade Connecting in Germany) The middle line is ground.
licence plate harness (ebay from Germany) I did not use the resistors. Also you can order all the plugs from DeyTrade so no need to order anything off ebay. See post #24 later in thread with all DeyTrade plug part numbers and links)
Nice work all around, and removing the license plate lights as a test was very smart.
Originally Posted by krburrell
OK I finally had some time over my holiday break to study this and have good news. This looks like an easy mod to perform once you take the rear bumper cover off. Looking at the wiring diagram I saw that the middle tail light actually has two lines and ground. One line is connected to the right tail light and the other is connected to the left tail light. Using the 4S harness I was able to determine the connector that plugs into the middle tail light (which is part number 4F0973703A). I also saw in the wiring diagram that the two license plate lights are connected together as a single circuit. I built a plug and play harness that connects into one of the license plate lights and feeds both lines of the middle tail light. I purchased both pieces to make the harness online. The licence plate harness came from an ebay kit to add LED lights and the other harness was a pre-made piece that had a 4F0973703A connector on it. I spliced these together to make this harness. I will go back and cleanup the harness with soldered connections and shrink sleeving to make it water proof then have the light installed on my car.
I checked the setup with the engine running to see if I got any errors and did not get anything. Also as a test I removed one licence plate light and did not get an error. I then I removed both licence plate lights and got an instant error as soon as I turned the key.
Here are the part numbers needed:
Middle Light:991-631-465-02
5X light mounting nuts: 999-076-056-01
Middle tail light harness: 42831100-PT (from DeyTrade Connecting in Germany) The middle line is ground.
licence plate harness (ebay from Germany) I did not use the resistors.
07-29-2018, 09:38 AM
