1986 505 Turbo - Detonation Sensor Lit Dimly

[trymes]

So, I replaced my oil pressure switch, much later than I should have, so I know will know if I experience a catastrophic loss of oil pressure, which is safe to say is a Good Thing®. This now means that the lamp test function of the cluster is working again, with the oil pressure, STOP, High temp, and Oil-level gauge function lighting up as they should. WOO HOO!

However, since I changed the switch, now I have this weird behavior:

1. Turn key on, then turn key off: detonation Sensor remains lit dimly.
2. Turn key on, start engine, turn key off: detonation sensor turns off completely, as it should.

Can anyone explain why I'm seeing this? Perhaps an issue in the cluster? I included a demonstration in this video:

 

[V-M]

Have you checked detonation ecu box? I dont remember if its located same as earlier model, in earlier model its located under dash so at if heater valve is leaking it leaks directly to box and its not water tight. So in time it consume moist and starts fail. If its okay remember at least turn it so at connector is down to prevent it happen.