Gearbox help
 

F125 switch fault is the first thing that springs to mind.
Does the car start and drive? Can you get the key out?

Gearbox help
 

Key works as normal goes in turns on and cranks if I leave key and try to take it out in any other position other than park it won't come out as normal.. I get my parking sensors when in reverse working as normal as the back end is up against the garage wall I can turn it over in park do you know difference between oval black plug on f125 switch and the round plug as in the extra pins and what they are for doing my gearbox swap the have diff pugs I've used the plug from gearbox that happened to go bad as for the gearbox I put in it has oval plug but because of engine wiring loom had to use round plug.. I've got the loom from other car that the reconditioned gearbox came from at cost of 2600 quid so rebuild but what would I be missing as connector has 10 pin as apposed to 8 on round plug

Gearbox help
 

Gearbox help
 

http://forum.a8parts.co.uk/album.php...pictureid=1378 what is the difference

The differences between the two versions of the switch are almost certainly the cause.

We'd need to know more about the age and details of your car and the car where the gearbox came from to comment further.
Also did you keep the F125 switch from your car and just move it to the new gearbox or graft on the other plug?

From your brief description above it's not at all clear what you did re the F125 switch and connections when swapping the gearbox, maybe describe it step by step so it's obvious.

How to rectify it, if you can, needs someone with an intimate knowledge of the interior and workings of the F125 switch.....
Now who might that be? ;)

Gearbox help
 

http://forum.a8parts.co.uk/album.php...pictureid=1409

http://forum.a8parts.co.uk/album.php...pictureid=1408

I've not done any splicing W8AND has round plug Y729 XGA had round plug I put the round plug on Y729XGA gearbox so it would plug into W8AND wiring loom so basically just swapped the f125 switch over

OK so not 100% clear (too many "rounds") as I don't know which car is which, but I think from that your car with the problem had the later gearbox/F125 with the 10-pin connector and the gearbox you installed came from an older car with an 8-pin F125.
So you still have a 10-pin F125 but mounted on a gearbox that initially had the 8-pin version?

Or is it the other way round?

Gearbox help
 

😂😅LOL sorry for the confusion I'm just so glad someone trying to help got carried away OK fresh start before any thing was done bother cars were both running. Y729XGA had reconditioned gearbox and oval plug on loom and f125 switch. Second car W8AND had round plug on loom and f125 switch W8AND had gearbox failure so I took it out and put Y729XGA gearbox in but I took of f125 and just swapped it over from W8AND now I have Y729XGA gearbox in W8AND car with round f125 switch instead of the oval f125 switch so as I could plug into W8AND loom... I sent pic of build sticker for both cars did you make sense of them.. Your helping a real novice here and it is well appreciated thanks🙏😁