So I am in the process of converting my 1970 Cutlass Convertible interior lights to LED. It should be stated that this car was a basket case and since reassembly the interior lights have not been tested or proven to work correctly. Also I do have the correct double contact bulbs. Almost everything seems to work as it should. If you open either door the front and rear courtesy lights come on. If I turn the switch for the map light, everything comes on. If I rotate the headlight switch to the right the rear lights come on but not the front. I know that the orange wire is constant 12v and the white wire with black stripe is switched ground. It seems to me the headlight switch is working because it does turn the rear courtesy lights on and off, and the door switches seem to be working because they turn all the light on and off when I open or close a door. I guessing that there is a bad connection on the white wire off the headlight switch, but where would I check? It appears there are two white wires coming off the headlight switch going to each door switch. I checked the connection at courtesy light connector but if it was bad then the lights wouldn’t come in when I opened the door right? Since the white wire off the headlight switch goes to the door switch I leaning towards a bad door switch. Anybody have any ideas if I’m on the right track? Anything else that would prevent only the front courtesy lights from on when i rotate the headlight switch?

 

The console is considered auxiliary lighting, and grounded by a white wire with black tracer at the door jamb switch. Since the console and main lighting grounds have no connection, the console lights won’t come on with the headlight ****.


I don’t have a manual in front of me, so I might be a little off on the specifics.

 

So to be clear the lights I’m referring to are the two lower flood lights on the courtesy light harness. All the other lights work like I think they should. So your saying when I rotate the headlight switch the only lights that should come in are the two in the rear armrest? I thought the two under the dash and the one at the rear of the console would come on too. Maybe they are working like they should then.

 

So after I had a chance to take a look at the wiring diagram it is working as it should. The front courtesy lights and console lights which are optional, are grounded by the white wire with the black stripe. It is only grounded by the door switches or the map light switch. The rear courtesy lights which would be a dome light on a hardtop, are grounded by the white wire. It is grounded by the door switches or the headlight switch. I think I am going to jumper the white and the white/black wires at once of the door switches. That way all of the lights would be able to be switched on by the headlight switch, door switches, or map light switch. I guess it makes sense on a hardtop that the headlight switch would only turn on the dome light, but on a convertible I think it would be more convenient to have all of the lower courtesy lights come on.

 

I thought that’s how it was wired. I ran into that issue when I modified my car with a RAP module from a mid 90s F body. I needed a door jamb terminal to provide a ground trigger to shut off the rap module when the door opened. Since I was already using all 3 terminals, I combined all the lighting on one terminal.

I am curious why Olds thought the lighting needed to be split into separate ground triggers. The only reasons I can think of is A: maybe too much current draw of all the lighting on one small door jamb switch contact (not a concern with LED lamps) or B: they were worried about blinding the driver with all the lights coming on. Turning on a dome lamp while driving so your kids can find something they dropped in the backseat is one thing, having every light blinding you is a different matter.