1990 740 Interior Light

Good day,

I have 2 1990 740's and a 1985 740.

The one 1990 I have had longest has had a problem with the interior
light located on the headliner. It fails to go one when the door is
opened.

All the lights work if you switch them on and off at the light unit
but not when the door opens

The side marker lights on the door work so it is not the switch on the
"A" pillars.

I never noticed it before as I don't drive in the dark very much, but
I recently discovered on the newer of the 2 1990's the light stays on
for a few seconds after the door is closed (unlike my 1985).

I assume that whatever "times" the light must be the cause of the
problem.

Anyone got an idea what/where that device is? Could this be the
problem?

TIA

jimB

 

I know where it is on a 240, but can't help there with a 740. '85 should
have the delay as well, my '84 240 has it and the 700 series was top of
the line.