ay gurus so I got a new one. I have a '97 Jaguar XK8 4.0. customer brought car in because the shift solenoid and brake lights were not functioning. Replace the brake light switch didn't help. Found out that the ignition switch wasn't grounding properly when the vehicle was in ignition on position. First I ran a new ground which cured the issue but left the vehicle in a state of power on all the time resulting in battery drain and car not being able to switch off. Next replace ignition switch. That seemed to fix the issue for a couple days. Now the vehicle is back in the shop with the same issue. Is there a reason why the ignition switch would stop grounding? Is there a way to run the ground so that car turns off properly when the key is in the off position? Fuses are good, battery is good, new ignition switch, new brake light switch. Any help appreciated
-Dark

 

To follow up I've retested the wires. After installing the ignition switch the first time it cure the issue. Now the same wire orange/white which is acting as the ground when the ignition is in the second position no longer has ground. Grounding this wire activates the brake lights and the shift solenoid. I just don't understand why it worked for a couple days and now lost the ground again. Checking over vehicle thoroughly will update if I have any progress

 

So I ended up wiring in another relay to power on when the ignition comes on. I wired this relay into the brake light switch so it grounds properly where the ignition's on, and And when you turn it off it cuts it out so it's not draining the battery. Only way I can think to solve this. But it works so if anyone else has this problem in the future it can't figure out why they lost their ground, adding a relay fixed my issue