Courtesy light trouble.

[Fredensborg]

My drivers side courtesy light switch has been broken for years, and I figured it should be a pretty simple fix to attempt. The actual switch is broken, the button will not pop out when the door is open, it stays permanently in the closed position. I ordered new switches and they physically work great, but electrically something is wrong and I have no idea where to begin to fix it. 
 

I tried installing the new drivers side courtesy light switch tonight to no avail…it is my understanding that the drivers side switch should have a 2 prong plug, and the passengers side should have a 3 prong plug…I seem to have 3 prongs on both of my plugs, and they appear to work intermittently depending on how you hold the wiring. Is this a grounding issue? Did someone incorrectly rewire this car at some point? My drivers side switch has 3 wires going to it, while my passengers side has 5. 
 

Now I’m no electrician, and I don’t really know how to read an electrical diagram. Does anyone have any suggestions as to what might be going on here? 


View attachment IMG_7881.MOV

 

[midlife]

The base configuration has a 3 pin door jamb switch on the driver's side and a 2 pin on the passenger side.  However, with the convenience harness as an option, the passenger side door jamb connector plugs into the convenience harness pigtail and a 3 pin actually goes to the door jamb to allow the seat back release to occur when the passenger door opens. 

The courtesy lights work when either the driver or passenger side doors open allowing current to flow from the green/yellow wire at the door jamb to the black/blue wires, which actually light the lamps.

 

[1sostatic]

The base configuration has a 3 pin door jamb switch on the driver's side and a 2 pin on the passenger side. 

That caught me out with my Green one -- and this is the problem when a previous owner had also been dicking about with the wiring
-- I ordered new and what I got was 2 prong... I tried to install to drivers side and found 3x wires.  one terminated out by previous owner... 

I learned the "don't assume you're working with originality" lesson here.

 

[Fredensborg]

The base configuration has a 3 pin door jamb switch on the driver's side and a 2 pin on the passenger side.  However, with the convenience harness as an option, the passenger side door jamb connector plugs into the convenience harness pigtail and a 3 pin actually goes to the door jamb to allow the seat back release to occur when the passenger door opens. 

The courtesy lights work when either the driver or passenger side doors open allowing current to flow from the green/yellow wire at the door jamb to the black/blue wires, which actually light the lamps.

Thank you for this explanation. While digging around in there and found this…the yellow plug I have inserted powers those latch release motors you mentioned….I didn’t even know I had them! What a cool feature. The other yellow plug doesn’t seem to do anything at all?? The one that is plugged in however, will power those latch releases no matter which of those 3 sockets it’s plugged into. The drivers side one kinda hangs up though, and doesn’t fully release that lever, I’m guessing that’s why someone unplugged it previously.
 

  Do you think my courtesy lights just have a weak connection in the wiring  of the gray plug? You can see in this video, it kinda works but only if you find the “sweet spot”. 


View attachment IMG_7885.MOV

 

[midlife]

The convenience harness has 2 male plugs: one for the seat back release with a thick wire, usually black, and the other for the seat belt light/relay system (thinner wire).  The thinner wire plugs into the 3 prong plug coming from the fuse box; the thicker wire goes to another yellow 3 prong plug coming from a power line coming through the firewall and attaches at the other end to the battery side of the solenoid.  Your picture appears to be the latter (firewall) power lead.

I can hear the video but I can't see any pictures, so I can't tell you what's going on.  If your passenger side courtesy light comes on but not the driver's side when you open the driver's door, then you probably have a faulty connection at the bulb/socket.  Each year (71,2,3) has slightly different wiring for the courtesy lights.  IIRC, the 73 underdash courtesy lights have a separate harness that starts on the passenger side and runs to the driver's side and stops, but may have outlets for door lights (option).  If this is correct, then you may have a broken wire between the passenger and driver's side bulbs.

 

[Fredensborg]

I can hear the video but I can't see any pictures, so I can't tell you what's going on. 

Here’s the video I was trying to upload…

 

[midlife]

It appears that the door jamb switch (at least that one...) works, but I can't tell if it is due to the plunger or your screwing around with the wires.  If the wires, then you have a bad crimp there. 

The courtesy lights should work when the door pin is out and off when the pin is pushed in. 

 

[Fredensborg]

It appears that the door jamb switch (at least that one...) works, but I can't tell if it is due to the plunger or your screwing around with the wires.  If the wires, then you have a bad crimp there. 

Ya, the switch works fine. I think it is the connection in the harness. Is it difficult to pull the wires and re-crimp? I don’t want to damage the plug on the wiring harness. 

 

[midlife]

The driver's side 3 pin door connector is quite fragile and the locking tabs are easily broken off.  However, most times the switch stays put when installed as most use a piece of duct tape to help it stay in place.