[italianguy63]

Background:

I am aware that many other folks have tried to figure this problem out before I tried to tackle it. For example I know "Lukeinva" worked alot on it. Since I am relatively new to the forum, however, I am ignorant to most of the history. However, Luke did give me some head's up info. and allowed me to ultimately figure this out. He's the one that told me the FCM was the villan.

Another fantastic gentleman of this forum "Mr. Incredible" helped me extensively on this project. He is extremely educated on the inner workings of the 300, and he also owned a "C" model for reference. Since we are opposite ends of the country-- there were a lot of pictures taken and a lot of e-mails sent. We probably asked every "what if" question imaginable. Ultimately, the solution to the problem was pretty "brute force"-- which I find depressing, because we actually had some pretty clever ideas throughout the process.

Mr. Incredible and myself started out by pouring over the schematics and parts lists. Then we began disecting our cars starting at the tail lights and moving forward. We found the differences in the rear fuse blocks, and I did a bunch of cutting & splicing of wires to try to isolate the turn function from the brakes; and combine the brake function to the 3rd brake light. The brake lights unfortunately are tied to other things back there (such as the ESP relay). The reason I am telling you this is... I tried everything we could think of and about 3 weeks of time to ultimately realize that the brake/turn function is controlled by the Forward Control Module (FCM), and there was no way to circumvent it. Both cars have the same part number for the FCM, so the issue is a "flash" issue. Without having the ability to reprogram the FCM and knowing what this function is tied to in the FCM data... it became a nearly impossible task. If someone has the ability to decode the FCM firmware/software there could possibly be an easier fix. But, it was out of our reach without extensive equipment.