I've been investigating the mysteries of my door contact switch wiring in my car. I found out the wire for the front passenger door contact switch has completely vanished and the black/blue wire coming from the driver's side of the dash goes through a sketchy bundle of tape before continuing to the rear passenger door contact switch. I'm guessing that this used to be a three-way junction and I simply need to splice in a wire going to the front passenger door.

But the real mystery is with the rear driver's side door. This one has a wire thankfully, but it does not seem to be connected with the rest of the circuit. More confiusingly, as the wire comes down the b-pillar to the floor, it goes backwards and enters the harness going towards the taillights. I thought that maybe the wire was crossing over to the passenger side to hook up with the rest of the circuit, but I don't see any point where this wire crosses over. I've tried to find a detailed diagram of the physical wiring, but haven't found anything helpful. Does anyone have any insights?

Hi aharres,

Insight, maybe? A wiring diagram, yes.

Go here (Copy then paste URL in new browser tab or window.):
http://www.v8volvo.se/mekartips/volvo/index.html

Click:
Files 140-240-260

Click to open or download the PDF file:
"System wiring diagrams Volvo 240 1992.pdf"

On PDF page 18, see the door, at grid 25-26 at C.

You'll see connection to fuse #9, the dome or courtesy light, and the chime box.

The door pillar switches, when the door is open and the plunger extended, connect to ground through the switch. When the door is open and the plunger extended, the dome light illuminates depending on dome light switch position and the chime sounds whether the key is in the ignition lock.

The switches can form corrosion under the boot whether the boot has ripped or not. So the circuit may not close.

Please see the circuit diagram.

Hope hat helps.

Questions?

Unemployed MacDuffed.
--
Jonathan Harshman Winters III: The Mightiest, Greatest, & Most Powerful North American Comedian & Comedic Actor in Perpetuity!

Thanks for the wiring diagram. I understand what you're saying. I've ruled out a failure of any switches. At this point I'm trying to physically trace the wire to find a fault.

I found some shady wiring and fixed the problem. The rear left door switch ends up going from the left b-pillar to the main harness and forward to the firewall.

Glad you remediated the issue! =^)

Yeah, that is sort of funny. Wonder if that was from the factory?

And the chime sounds (peels?) also when the door is open.

Also, you verified the three-position dome light switch works as Off all the time, on when a door is open, and on all the time.

You can install way brighter LED festoon bulbs for the (ceiling?) dome light also for both the passenger dome light and the cargo area dome light.

Sure Happy it's Wednesday (All Day Long)!

Thank you.

(Got No) Buttermilk Boyeeeeeeeee.
--
Jonathan Harshman Winters III: The Mightiest, Greatest, & Most Powerful North American Comedian & Comedic Actor in Perpetuity!