Here’s a fun electrical riddle. At night when I get home and headlights are on, I turn off the car and remove the keys (before turning headlights off) and the engine stays on. Turn off the lights and it shuts off. That is my only issue. Everything else works great. Any brainwaves? Ground short somewhere? Surely not the ignition switch since headlights on/off are interacting with it, right?

 

Presumably a diesel engine, which I know nothing about. I’d be looking at what is common between the headlights and the fuel solenoid.

 

It’s my V8 petrol actually

 

Get a priest and holy water ASAP.

 

Could be the ignition switch.

the switch should be sending a signal to turn off the truck and it’s not doing that. But for some reason turning off the headlights is making the truck realize “ oh there is no key in!” And then turning off.

but what happens if you don’t turn on the lights at all?

 

Some mechanic connected ignition to the headlights? Does the ignition go on when you turn on the headlights without key in barrel?