Hey drivers, I am ready to turn the 92 740 over to my daughter and realized that it has no door chime, key ( left in ignition) chime or seat belt warning. After some searching here it seems that there is supposed to be a relay labeled M but there are no contacts in the relay panel in location M.
I don't know if this is related but the dome lights do not come on when the doors open, only the map lights do. Both the passenger and cargo dome lights work when I throw the switch manually.
Any help you can provide will be greatly appreciated, I want to be sure the car does all the things it's supposed to do.
Thanks,
Andrew

 

The Blue Relay with the speaker vents:





I taped the relay so the sound was quieter.


I don't know what else is tied to that relay, but it could also dome light trigger.

Or the switch itself is bad for the trigger.

 

Thanks for the picture, I don't have that one in the car! I will grab one from the parts car.
Happy new year.
Andrew

 

on the 740/940's, the timer for the dome light is integral into the light assembly on the roof. for some wierd reason, its wired so the DRIVERS door triggers the timer, but the other doors just go on/off.

the drivers door switch goes to both the dome light and the key warning dinger. looks to me like unplugging the dinger woudl NOT affect the dome light

question, does the drivers door courtesy light work? eg, open the door, and the red light near the latch lights up? if not, then there's likely a problem with the switch, unless its fuse 5 (which powers both the dome light and the door courtesy lights)

the door switches have two contacts, and when the door is open, they ground both of them via the screw on the switch to the chassis. the seat belt reminder/door open with key circuit is on fuse 9

 

It may be a blessing not to have those annoying dingle bells...
Cars in Europe don't have them...

 

Ok, thanks for the additional info.
All of the red courtesy lights work, I pulled down the dome light but don't see anything that looks like a timer device, just contacts for the bulbs.
However, I will update if I figure it out.
Andrew

 

there's a tiny chip on the little circuit board on my 1992 740's dome light

 

Yes they do, my 2005 C70 convertible rings all the time!

 

I had an issue with the non-stop chiming after closing the roof manually although one of the cables snapped so I couldn't get it completely closed- was about 2 inches from closed at the back. Chime stopped as long as I locked the roof using the tool in the right hand side of the boot. Funnily enough once I fixed the cable and the roof was closed the Chime wouldn't stop at all. So I just pulled the fuse that controls the door Chime and few other not so vital things and that killed the roof chime I think on mine it was fuse 22(?)