Lights on Fuse 12

[orbitron3000]

I have referenced these two threads, but am having different problems:
http://dmctalk.org/showthread.php?4574-Interior-lights-amp-door-ajar-light-issues
http://dmctalk.org/showthread.php?1748-No-interior-courtesy-lamps

The front interior light and rear luggage light are behaving strangely. The rear light barely lights at all. I have tested the black and solid purple wires, and get ~12V with no other lights on. When the front interior light is on, which looks like it gets normal brightness, I get about 5.5V-6V on the rear light harness. When the glove compartment light is on, other lights visibly dim, which I don't remember happening in the past.

Both the rear and front interior lights are LEDs, the glove lamp is still incandescent. I have Dave's dome light dimmer, and it was functioning properly...for the front light (the rear light never dimmed properly). However, the lights in the dim position no longer light. I have checked the diodes in the driver footwell, and they seem to be in working order. The door lamps also work properly. I am trying to figure out why the lights don't work all in harmony and why they dim so much when more than one is on at a time.

[WelmoedJ]

I have referenced these two threads, but am having different problems:
http://dmctalk.org/showthread.php?4574-Interior-lights-amp-door-ajar-light-issues
http://dmctalk.org/showthread.php?1748-No-interior-courtesy-lamps

The front interior light and rear luggage light are behaving strangely. The rear light barely lights at all. I have tested the black and solid purple wires, and get ~12V with no other lights on. When the front interior light is on, which looks like it gets normal brightness, I get about 5.5V-6V on the rear light harness. When the glove compartment light is on, other lights visibly dim, which I don't remember happening in the past.

Both the rear and front interior lights are LEDs, the glove lamp is still incandescent. I have Dave's dome light dimmer, and it was functioning properly...for the front light (the rear light never dimmed properly). However, the lights in the dim position no longer light. I have checked the diodes in the driver footwell, and they seem to be in working order. The door lamps also work properly. I am trying to figure out why the lights don't work all in harmony and why they dim so much when more than one is on at a time.

- LEDS have a different way of dimming than incandescent bulbs.

- Concerning the fact that you mentioned having light problems previously to using LEDS I presume the connections at the dome and luggage units may be wrong.
John Hervey has a nice picture on his website on how to correctly connect those wires.

[Bitsyncmaster]

If you turn off both dome lights, do all the other lights seem to work? If so, this sounds like you have a bad ground on the dome timer socket. The only time the dome timer conducts ground current is driving the dome lights. That black wire in the socket is a "daisy chain" of wires that starts at the far right socket. So the bad connection could be in any of the front sockets. Takes an ohm meter to find which one it is. Other option is to install a new ground wire but then your other front relays may have problems also.

[orbitron3000]

Using a multimeter I've found that there seems to be (assuming that the meter is accurate) about 6.5ohms between the dimmer relay ground and the cluster in the back of the engine bay. I did not check the relays to the right or left yet. Once I find the culprit, what is the best way to fix the bad ground?

[Bitsyncmaster]

Using a multimeter I've found that there seems to be (assuming that the meter is accurate) about 6.5ohms between the dimmer relay ground and the cluster in the back of the engine bay. I did not check the relays to the right or left yet. Once I find the culprit, what is the best way to fix the bad ground?

If you can pull the pins and solder them, that should fix it. But you may have a hard time soldering if your pins and wire are tarnished. If you can find the faulty pin, pull it and recrimp (you can use vise grips) that pin.

[orbitron3000]

If you can pull the pins and solder them, that should fix it. But you may have a hard time soldering if your pins and wire are tarnished. If you can find the faulty pin, pull it and recrimp (you can use vise grips) that pin.

I'm not sure what you mean. Do you mean to pull the wires from the relay sockets and recrimp them? And if push comes to shove, can I simply run a new wire from the grouped ground behind the seats to provide new grounds for the relay banks?

[Bitsyncmaster]

I'm not sure what you mean. Do you mean to pull the wires from the relay sockets and recrimp them? And if push comes to shove, can I simply run a new wire from the grouped ground behind the seats to provide new grounds for the relay banks?

Yes, that is what I mean.

I simply ran new wires. One from each relay to one common wire that goes back to the rear ground group. I never liked using two wires crimped into one terminal.

[orbitron3000]

Yes, that is what I mean.

I simply ran new wires. One from each relay to one common wire that goes back to the rear ground group. I never liked using two wires crimped into one terminal.

I think I'm going to do that as well. Thanks very much for your help!

[orbitron3000]

Well when I put a dedicated ground to the dimmer relay, the lights at first worked flawlessly. Then overnight, something changed. When I went to finish putting the car together today, the interior lights either didn't work or were extremely dim. So, I added a ground wire directly from the battery to the dimmer relay and the interior lights start out dim, and just kind of fade away as if the battery was dying. However, the battery still reads a solid 12V on the multimeter. Even the glove box light (incandescent) starts out very dim and just slowly over maybe 20-30 seconds. What could be the culprit here? I've tested the ground on the glove box light and there is about 1 ohm.

Other symptoms I've noticed: the door ajar light no longer functions, the door lights themselves are extremely dim.

All other electrical systems seem to be in working order.

I've long past my expertise here and beginning to get a little worried -- if the lights aren't working, what else isn't or is soon to go? :confused:

[DeloSTM]

Bypass the door diodes with jumpers. Don't leave it that way unless you have a LED in the door ajar light.

[Bitsyncmaster]

Your bad ground may have damaged the dome timer unit. Send it back to me and I will test it. If it is bad, I will send you a new one.

[DMC5180]

Also try Disconnecting the Battery for 15 seconds and reconnect. I occasionally have to kill all power to allow the Digital dimmer to reset itself. This does not effect programing at all.