Dome light help

[Alan]

My dome lights don't come on when I open either door. I think it's the interior lamp delay unit. I'd like help proving it.

When I open either door, the appropriate door lamps (amber/red door edge lights) come on. I have incandescent bulbs in original dome lights. If I switch either of them on at the housing, they both come on as they should. The glove compartment light works as it should.

I think all my symptoms point to one common point of failure between both dome lights not working with the doors. That's the interior lamp delay unit. Is there a good way to test it?

I want to replace it with Bitsyncmaster's unit and LEDs... but I want to troubleshoot the system first so I know it will work when I do.

As an aside, Bitsyncmaster's Dome Light Dimmer module has the warning that it requires LEDs that don't have a switching regulator. Can someone refer me to specific LEDs that are the right type to work with Dave's dimmer?

Thanks,
Alan

[81dmc]

Might be one of the three diodes in the driver's footwell and/or a ground wire broke off the female spade on the door plunger. I had a bad diode.

Once I get to my car, I will tell you what color wires to look at.

[Alan]

Thank you.

It seems the door switch wiring has to be good. Otherwise, the wiring for both would need to be bad and I'd think the door lights themselves wouldn't work.

I'd think the diodes for the door lights have to be good or they'd both have to have gone out at the same time.

The diode for the delay unit seems like another possibility, though.

Does my thinking seem correct? And then, how to determine if it's the delay unit or the diode?

[81dmc]

It's the diode then. I don't even have a dome light module installed.

BTW, door lights and dome lights run off different diodes.

[Bitsyncmaster]

The door lights will work with or without diodes. The dome lights will only work with good diodes from the door switches if the dome lights are set to "auto" position.

Do your dome lights work when you switch them to manually on? That could be forward or backward depending which way the dome unit is installed.

[Alan]

Do your dome lights work when you switch them to manually on? That could be forward or backward depending which way the dome unit is installed.

Yes, I just confirmed, the dome lights work manually, normally. If it helps, the door lights only work on their respective sides via their respective plunger switches.

[81dmc]

I may have an extra diode I can send you. I removed it after I reinstalled Dave's Idle ECU.

[Bitsyncmaster]

Check that the three diodes still have the wires attached. The diodes are by the drivers right foot in the harness.

[Jonathan]

Alan,

Did your dome lights work before as they were intended? Have you owned your car going back that long? Did you replace the light fixtures at some point?

The reason I ask is that I struggled getting mine working, with new fixtures or the old, until I realized the wiring is counterintuitive to how you think it should go between the "auto" and "manual" modes (with the doors and without the doors that is).

I had a thread discussing it at one point and I'll see if I can find it or the drawing that helped me sort it out.

[Alan]

Alan,

Did your dome lights work before as they were intended? Have you owned your car going back that long? Did you replace the light fixtures at some point?

The reason I ask is that I struggled getting mine working, with new fixtures or the old, until I realized the wiring is counterintuitive to how you think it should go between the "auto" and "manual" modes (with the doors and without the doors that is).

I had a thread discussing it at one point and I'll see if I can find it or the drawing that helped me sort it out.

I've owned it under a year. I've made no changes to the dome lighting. The door lights are LEDs now. The dome lighting is all stock as far as I know... but I don't KNOW the PO didn't do something.

The dome lights did work properly for a while since I've had the car. I don't recall for sure, but I don't think the dome lights started failing right when the door LEDs went in. Any possibility of a relationship there, though?

My next step is to see about the connections at the diodes. I'll need to find them first.