Location: Syracuse, UT
Posts: 635
My VIN: 2087
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?Originally Posted by David T
Jared L.
June '81, manual, black inter. VIN 2087
Other cars: 2012 Toyota Sienna, 2007 Mazda 6, 1999 Jeep Cherokee
DeLorean blog: http://deloreanblog.blogspot.com/
Location: Syracuse, UT
Posts: 635
My VIN: 2087
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?
Jared L.
June '81, manual, black inter. VIN 2087
Other cars: 2012 Toyota Sienna, 2007 Mazda 6, 1999 Jeep Cherokee
DeLorean blog: http://deloreanblog.blogspot.com/
Location: Syracuse, UT
Posts: 635
My VIN: 2087
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?
Jared L.
June '81, manual, black inter. VIN 2087
Other cars: 2012 Toyota Sienna, 2007 Mazda 6, 1999 Jeep Cherokee
DeLorean blog: http://deloreanblog.blogspot.com/
Posts: 446
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):
P8261449.jpg
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:
Interior Lights Simplified Schematic.jpg
Don't make me wait 5 years.
Ron
Last edited by DMC-Ron; 11-23-2017 at 04:07 AM.
Location: Northern NJ
Posts: 8,579
My VIN: 10757 1st place Concourse 1998
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.
David Teitelbaum
Location: Austin MN
Posts: 581
My VIN: 03500
This is the diode bundle your looking for. Doors to dome lights go through this bundle.
Dave B.
Last edited by WHO1DMC; 11-24-2017 at 02:41 AM.
Location: Mebane, NC
Posts: 346
My VIN: 06668 81' Grey interior, 5 speed, Grooved hood. Previous owner of 16301, in 2001. Found Nov 2019, a
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.
Location: Austin MN
Posts: 581
My VIN: 03500
Yes
Posts: 446
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.
Interior lights wiring.JPG
Hope this helps,
Ron
Last edited by DMC-Ron; 04-04-2018 at 03:50 AM.
Posts: 4,807
My VIN: 3937
Additional explanation and photos of the wiring mistakes Ron is mentioning here: http://dmctalk.org/showthread.php?11...l=1#post174048
Sept. 81, auto, black interior
Reply With Quote
