Good day. I used 14 gauge wire. Also I use heat shield on the PCM. My thinking is that it gets a lot of heat from under the engine bay .
Good luck
Aloha Nick! Went in last Friday to a Ford service/dealership that would take my truck in and do the swap/flash/reprogram! Unfortunately the cost here in California is high, $220/hr or per item! Better than another one in my area that was $260/hr!
My mechanic, a former Ford master mech, said to me, it only takes 5 mins to pop out the PCM/ECU and 15-20 mins to flash the computer but sadly you will probably be hit with a minimum. So, to flash my new used PCM was $220.00. To physically take out and install my new used PCM was $220.00. On top of that, I only had one remote on me and they said I needed two for the programming, so that cost me another $75.00.
Here's the good news, in two hours I got back my vehicle and it was running well. Something I did not check was that both the new remote and the old remote worked. When I got home, my old remote did not work. The dealership contacted me and scheduled for a tech to drive out to me, over 30miles away. I located another original key that came with my vehicle when my father first purchased it. Well, that other original key proved important! When the tech came, I gave him all the keys, 3 total and the two remotes. That 3rd key was tied to my other PCM which also was tied into my original remote. By programming/cycling the 3rd key, it brought on the old remote and it held is programming along with the new remote. All 3 keys, one was made later by me all turn on the truck now! This service call by this Ford was free, talk about resolving an issue!
The Ford Tech said to me, that this is a more common problem than people know, the PCM ECU having issues. And instead of owners taking the time to do what you all helped me out with, troubleshooting, getting a good used PCM that was the same exact model/box in my truck and flashing it, they sell/scrap their vehicles. I also want to thank my local Ford parts supplier that was frustrated with his service people for not taking in my truck at $260/hr and working with me! He took my VIN number and checked it, told me what model number PCM I had so I could locate a used one.
So, I hope to locate a good rebuilder of these PCM's to have my original one repaired. I wasn't able to paint it with the paint but I hope to find a way to wrap the PCM in some type of heat shield/insulation. Next is to get the additional grounding attached! Mahalo!