FAIRXF 5 Posted July 19, 2020 So I recently bought an XF sedan that's been 5-speed converted it was originally 4-speed manual and the reverse switch hasn't got anything plugged on to it and I'm wondering where the wires would be located to solve this issue, eg what colors were the original 4-speed reverse light switch wired too? Share this post Link to post Share on other sites
deankxf 20,288 Posted July 19, 2020 if you follow the speedo cable wires to the plug near the firewall, there should be in the same plug(rectangle plug with 7 wires of an 8 hole plug i think) 3 are for speedo(you followed this from the sender on the gearbox) 2 should be looped (this is the starter wire inhibitor if it was auto) and the other 2 are reverse lights, they should reach the T5 switch from memory Share this post Link to post Share on other sites
FAIRXF 5 Posted July 19, 2020 1 hour ago, deankdx said: if you follow the speedo cable wires to the plug near the firewall, there should be in the same plug(rectangle plug with 7 wires of an 8 hole plug i think) 3 are for speedo(you followed this from the sender on the gearbox) 2 should be looped (this is the starter wire inhibitor if it was auto) and the other 2 are reverse lights, they should reach the T5 switch from memory ill have to take a look tomorrow but those 2 reverse light wires both got to either side of the switch? Share this post Link to post Share on other sites
deankxf 20,288 Posted July 19, 2020 23 minutes ago, FAIRXF said: ill have to take a look tomorrow but those 2 reverse light wires both got to either side of the switch? yeah, if you joined them together the lights would come on if you wanted to test them prior Share this post Link to post Share on other sites
FAIRXF 5 Posted July 19, 2020 4 minutes ago, deankdx said: yeah, if you joined them together the lights would come on if you wanted to test them prior Today when I was underneath i noticed 2 wires joined together long enough to reach the switch but the reverse lights still don't work and i wasn't getting power at the ends of those either Share this post Link to post Share on other sites
gerg 10,871 Posted July 19, 2020 Did they come on when you bridged them like Dean said? That would be the first bit of diagnosis to do before diving into anything else. Sent from my CPH1607 using Tapatalk Share this post Link to post Share on other sites
FAIRXF 5 Posted July 19, 2020 Just now, gerg said: Did they come on when you bridged them like Dean said? That would be the first bit of diagnosis to do before diving into anything else. Sent from my CPH1607 using Tapatalk No, it was already bridged or twisted together and they still don't work and have no power at the wires Share this post Link to post Share on other sites
gerg 10,871 Posted July 19, 2020 OK then it's not the reverse switch (yet). I'm not terribly familiar with what fuses do what in an XF but the reverse lamp circuit should get supply from the ignition. So if you check for supply at the fuse with ignition on, that would narrow it down more.There should be a connector in the engine bay coming off the main loom that goes down to the box for all the devices on there (speedo, reverse, neutral). That one you bridged may well be for a neutral switch which if fitted, lives in the shifter housing on the old 4 speed. That tells the computer to do certain things with timing, etc when in neutral.Sent from my CPH1607 using Tapatalk 1 deankxf reacted to this Share this post Link to post Share on other sites
deankxf 20,288 Posted July 19, 2020 i don't remember the colour code of the wires, but the other 2 in that plug need to be joined or the car won't start. (other than the 3 for the speedo) if the lights aren't working, you'd just have to start checking fuses, globes themselves, the earth for the tail lights. Share this post Link to post Share on other sites
FAIRXF 5 Posted July 19, 2020 3 Just now, deankdx said: i don't remember the colour code of the wires, but the other 2 in that plug need to be joined or the car won't start. (other than the 3 for the speedo) if the lights aren't working, you'd just have to start checking fuses, globes themselves, the earth for the tail lights. I checked power at the back of the globes and there wasn't any power there either, the globes are perfectly fine Share this post Link to post Share on other sites
FAIRXF 5 Posted July 19, 2020 10 minutes ago, gerg said: OK then it's not the reverse switch (yet). I'm not terribly familiar with what fuses do what in an XF but the reverse lamp circuit should get supply from the ignition. So if you check for supply at the fuse with ignition on, that would narrow it down more. There should be a connector in the engine bay coming off the main loom that goes down to the box for all the devices on there (speedo, reverse, neutral). That one you bridged may well be for a neutral switch which if fitted, lives in the shifter housing on the old 4 speed. That tells the computer to do certain things with timing, etc when in neutral. Sent from my CPH1607 using Tapatalk When i get home from work tomorrow ill take some photos of what it looks like currently 2 gerg and deankxf reacted to this Share this post Link to post Share on other sites