Interior lights & door ajar light issues

[Stainless]

I have referred to the following thread, but have different questions: http://dmctalk.org/showthread.php?1748-No-interior-courtesy-lamps&highlight=courtesy

I was having the same issue as the OP of the other thread, meaning that my courtesy lights turn on when set to the "always on" position, but nothing ever happens in any of the other two positions. I first checked to see how the lights were wired and I found that the solid purple wire is on the one side and the purple/white wires and the black wire are on the other side. Since the light does turn on, I figured that the wiring was fine for both lights. I then decided to pull the lamp delay relay from behind the passenger seat to see if the lights come on, but they still didn't come on when the doors were opened. Keep in mind that the door ajar light would come on as well as the door marker lights when the doors were opened, so the car is definitely recognizing when the doors are open.

Conceding defeat, I reinstalled the lamp delay relay, but when the doors were closed, the door ajar light still stayed very dimly lit. I was wondering what I did wrong here. I thought I installed the relay the same way that it came out. I decided to pull the relay again, and the door ajar light goes completely off again when the doors are closed. Ideally I would like the courtesy lights to come on when the doors are opened, but since they've never functioned like this since I've owned the car, it's not a "must have" for me, but a "nice to have" feature.

In the other thread, someone mentioned some diodes in the driver side foot well, but I am not sure what those are to check. Thanks for the help.

[Bitsyncmaster]

Do you have and LEDs in the door adjar and dome lights? If so, you should not have the OEM dome timmer installed. You still have an issue which sounds like your diodes. There are three diodes in the harness by the drivers right foot.

[Stainless]

Do you have and LEDs in the door adjar and dome lights? If so, you should not have the OEM dome timmer installed. You still have an issue which sounds like your diodes. There are three diodes in the harness by the drivers right foot.

There is an LED in the door adjar light, but the dome light looks exactly like this light from DMC, which looks like an incandescent bulb:
https://store.delorean.com/p-6913-bulb.aspx

So if I removed the white OEM dome timer, and all else is good, should the lights still come on when the doors are opened? Do I need to switch the incandescent courtesy bulbs to LEDs as well? How do you test if the diodes are good/bad, and if they are bad, where do you recommend on finding replacements? This is the first electrical issue that I've had to deal with on this car besides the radio antenna. Forgive my ignorance. Thanks.

[WelmoedJ]

Are you sure that the wires for each of the driver's side switches belong to the same pair?
IIRC interchanging them may cause alike trouble.

[stevedmc]

Remove your door dimmer module. It won't work if you have LEDs. I removed mine about 2 years ago and my lights come on and off just fine but they don;t gradually dim out.

Dave sells a nice module that will give you the dim feature with LEDs if that is what you desire.

Back to the problem at hand. Have you verified that you have door plungers and that they are hooked up? These are little swiches (plungers) that get pressed in when you close the door. Sitting in the driver seat you should see one to the left of your feet.

[Bitsyncmaster]

Since your door lights come on the door switchs must be working. The dome lights drive through the diodes. So the diodes would be the place to start looking.

[Stainless]

So this weekend I removed the stock door relay and the door ajar light works as it should again. It comes one when one or both of the doors are open and goes completely off when they are both shut. Problem #1 is solved.

Problem #2 is still bugging me. The interior courtesy lights never come on when the doors are opened. I looked under the dash while I was removing the binnacle this weekend for an unrelated repair, and I saw wires coming off the other side of the door plungers, but I didn't trace where they went because they went behind the carpet. Where are these diodes located that may need replacing, and where do I get replacements if they are indeed needed?

[Bitsyncmaster]

Where are these diodes located that may need replacing, and where do I get replacements if they are indeed needed?

In harness right side of drivers right foot.

[Stainless]

Is this what I'm looking for?

https://store.delorean.com/p-7181-diode-1-ampa75294.aspx

[David T]

Make sure the courtesy lights are wired up correctly. Make sure the wires going to the door plunger switches are hooked up correctly. On the driver's door there are two sets of two wires each being taped together. Do NOT mix (cross) them up. The door plunger lights should control the 3 lights on the bottom of each door. On the driver's side there are two switches, one for the interior lights and the other for the key-in-ignition buzzer. Most owners have that one disconnected. I have to check my lights but I think you have the wires for the interior courtesy lights on the wrong terminals.
David Teitelbaum

[Stainless]

Make sure the courtesy lights are wired up correctly. Make sure the wires going to the door plunger switches are hooked up correctly. On the driver's door there are two sets of two wires each being taped together. Do NOT mix (cross) them up. The door plunger lights should control the 3 lights on the bottom of each door. On the driver's side there are two switches, one for the interior lights and the other for the key-in-ignition buzzer. Most owners have that one disconnected. I have to check my lights but I think you have the wires for the interior courtesy lights on the wrong terminals.
David Teitelbaum

The odd thing is, the lights on the doors work fine when the doors open and go off when they are closed. The key-in-ignition buzzer seems to be working as well. What are the symptoms if the wires are on the wrong terminals?

[Stainless]

I may have spoken too soon about my door buzzer working. My key buzzer goes on whenever I have the key in the ignition and it is set to the OFF position, regardless of the door being open or not. The way I understand it is that this should only make noise if the key is in the ignition and the door is open. Am I correct in that understanding?

[Stainless]

Well it's been over 5 years and I still haven't dedicated enough effort to try and figure out why the interior lights don't come on when the doors are opened.

To recap current state: door lights come on and off just fine when plungers are pushed in/out. Interior dome lights work when manually turned on.

Possible suspects include the diodes and incorrect wiring. Anyone willing to help point me in the right direction?

[DMC-Ron]

Well it's been over 5 years and I still haven't dedicated enough effort to try and figure out why the interior lights don't come on when the doors are opened.

To recap current state: door lights come on and off just fine when plungers are pushed in/out. Interior dome lights work when manually turned on.

Possible suspects include the diodes and incorrect wiring. Anyone willing to help point me in the right direction?

Well let's not waste any time :(

First thing to check is if the wiring is connected correctly at the lamp fixture (easy to get these wires turned around). The important thing to check here is that the solid purple wire is connecting to the terminal that directly connects to the bulb (purple does not go thru the selector switch). The purple/white wire and the black ground wire are connected to the terminals that go to the switch. Here is a photo of my rear interior light (My car has the newer style where the lens serves as the rocker switch, yours may have a small lever switch):
54670

Now to the circuit: Below I have attached a schematic purposely cut and pasted to show the pertinent wiring (ignore the truncated wiring). Here are some observations based on your description:
1. If, as you mention, your DOOR AJAR light illuminates when only the driver door is open and also when only the passenger door is open, then you know both diodes shown at the doors are OK.
2. The interior lights should come on when doors are open regardless of whether the lamp delay module is working or even in the socket. If they don’t, then either the wiring or the diode shown near the lamp delay would be suspect. There are some tests you can do at the lamp delay socket. First you can measure whether power is getting there when the interior lights are set to “door” mode. Second, you can use a jumper at the lamp delay socket to verify that the interior lights will come on when grounded (this would verify the wiring from the interior lights to the lamp delay socket).
Here is the abbreviated wiring schematic:
54671

Don't make me wait 5 years.
Ron

[David T]

Some other quick things to check. On the driver's door there are 4 wires. They are taped into 2 groups of 2. Make sure each group goes to each switch and they are not "crossed". The other thing to check is that all 3 door switch plungers have a rubber tip on them. If not, a short piece of rubber tubing can suffice. Without that tip (or piece of hose) the switch will not get fully depressed when you close the doors. As Ron said, make sure the lights are connected correctly and the switch is in the correct position for the lights to go on and off. Don't forget there are TWO lights, one over the dash and one on the package shelf. If this doesn't get the lights to work correctly you will have to go "deeper" into the circuit.

[WHO1DMC]

This is the diode bundle your looking for. Doors to dome lights go through this bundle.



Dave B.

[hippieman9]

So reading this thread, I am having an issue with the dome light over the dash not working with the doors open. The On position works. The package shelf light works correctly in all positions. Now I have converted to LEDs and removed the white timer relay. So The rear interior light works with the doors, no problem, front one, just the on position. So my question is can I swap the diodes to test to see if one is bad? Meaning that if the rear light is working, then I switch the diode, the front light will work. Then if I find that that is the case, I can get a new diode.

[WHO1DMC]

So reading this thread, I am having an issue with the dome light over the dash not working with the doors open. The On position works. The package shelf light works correctly in all positions. Now I have converted to LEDs and removed the white timer relay. So The rear interior light works with the doors, no problem, front one, just the on position. So my question is can I swap the diodes to test to see if one is bad? Meaning that if the rear light is working, then I switch the diode, the front light will work. Then if I find that that is the case, I can get a new diode.

Yes

[DMC-Ron]

So reading this thread, I am having an issue with the dome light over the dash not working with the doors open. The On position works. The package shelf light works correctly in all positions. Now I have converted to LEDs and removed the white timer relay. So The rear interior light works with the doors, no problem, front one, just the on position. So my question is can I swap the diodes to test to see if one is bad? Meaning that if the rear light is working, then I switch the diode, the front light will work. Then if I find that that is the case, I can get a new diode.

There is one diode common to both front and rear interior dome lights. So a bad diode would generally affect both interior lights.

There are additional diodes that isolate the door lighting so the door lights work only with their respective door switches. Here's how you can check those door diodes:
1. Check if your door ajar warning light works when either door is open. (i.e. ON with drivers door open and passenger door closed. and also ON with passenger door open and driver door closed).
2. Now with both doors open, check to see if the lights in the door turn off with their respective door switch (just push in the door plunger switch).

If 1. and 2. are true then the door diodes are working.

That leaves the one diode that is common to both interior dome lights. Since both interior lights use the same diode, if one dome light is working then the diode is working.

If this is the case (seems to be from your description), then your problem with the dash interior dome light might be incorrect connection or a wiring problem. Most commonly it is incorrect connection of the wires at the dome light (this can happen when the light was repaired or replaced or when LED lights were installed if the fixture was disconnected then reconnected improperly). Often the wires get reversed when reinstalling the fixture. Otherwise it might be a wiring issue, specifically the purple/white wire. Given your problem is with the front interior light there are two connections to check: First is at the light itself, making sure that the connector is in good condition and making good connection at the fixture (also check the fixture switch to make sure it is making a good connection when selected to "door" operation. Second is where the two purple/white wires connect to the diode, check to make sure both wires are connected and neither has worked loose.
55831

Hope this helps,
Ron

[Jonathan]

Additional explanation and photos of the wiring mistakes Ron is mentioning here: http://dmctalk.org/showthread.php?11960-Interior-dome-lights-can-work-with-LEDs-and-delay-unit-relay&p=174048&viewfull=1#post174048

[hippieman9]

OK, So the driver door lights and door open warning light works as it should, the passenger door lights and open warning switch work as it should. I have an aftermarket dome light in the front position, the one that the lens rocks back and forth for the different settings. I noticed that when pushing in the passenger door switch manually, jiggling it , the light would flicker on. it won't stay on, just can see it flicker.

[hippieman9]

OK, So the driver door lights and door open warning light works as it should, the passenger door lights and open warning switch work as it should. I have an aftermarket dome light in the front position, the one that the lens rocks back and forth for the different settings. I noticed that when pushing in the passenger door switch manually, jiggling it , the light would flicker on. it won't stay on, just can see it flicker.

Correction, I double checked both doors and the light will flicker with the driver side switch too. Also I attached a pic of the light wiring and the diodes.

[hippieman9]

OK, Well, mystery solved. I switched the front and rear dome lights and the front worked fine. So.. It was a bad light housing.