Door lights - wire routing

[Rich_NYS]

I've removed the interior on two Deloreans, but don't recall: how/where are the feed wires routed from the plunger switches?

The passenger door lights and front dome stays on.

I'm testing a hard ground on the passenger feed with the circuit open at both doors, both interior lights, and the relay pulled. (Drivers side has a light ground.)

So, I'm trying to trace a ground and would like to find the best location[s] to isolate.

Thanks......

[David T]

Refer to M:18:12 for the schematic. Make sure the circuits are not "crossed" on the driver's door. If you mix up the wires you can get weird results. The wires are taped in 2 groups of two. One group is for the door buzzer and 1 group is for the door lights. You could have an inadvertent ground (a wire shorted to ground) or a bad diode. One way to troubleshot is to "divide and conquer". Test each door for example. Point is to disconnect sections of the circuit and test it before hooking it back up and testing other sections. When testing this kind of circuit the first thing to do is to pull the all bulbs and see if they are correct, correctly installed, and not corroded. Oftentimes they are the source of the problem. If you do find a problem don't stop. Many times there can be multiple problems with one problem hiding others. Don't close up everything until you have successfully tested everything and are satisfied it is working correctly. One other spot to check is where the harness feeds into the top of the door. The wires can break or get pinched, especially if the door was removed. Rare but it can happen.

[Rich_NYS]

Thanks David, the schematic doesn't show the routing of the wires....just illustrates the circuit. I'm trying to locate the wires to find the physical fault.

Nothing is crossed, and I'm familiar with "which wires go where" on the drivers side. The issue is a ground on the feed wire somewhere....I just need to find it. I suspect the feed to the passenger side.

So, I'm trying to find out where/how the [Purple, Purple/Pink] feed wires are routed. I don't think the White/Purple is part of the issue but would be good to know how those are routed as well.

Thanks again.

[Ron]

I've removed the interior on two Deloreans, but don't recall: how/where are the feed wires routed from the plunger switches?

The passenger door lights and front dome stays on.

I'm testing a hard ground on the passenger feed with the circuit open at both doors, both interior lights, and the relay pulled. (Drivers side has a light ground.)

So, I'm trying to trace a ground and would like to find the best location[s] to isolate.

Thanks......
You can turn the front dome light off with its switch, right?

??? A a "hard" ground on the passenger feed should make fuse 12 blow...

Assuming everything is wired correctly-
If the passenger door lights stay on, either the PK (Purple /Pink) wire is shorted to ground (bad switch?) or the diode with PK wires is bad (reversed/shorted internally). IF the latter, you also have a short to ground from the other side of the diode (PW or RU wire).

Disconnect all but the PK wires from the diode. Then see if the passenger side switch turns the passenger door lights on and off. (And what happens with the front interior light.)

[Rich_NYS]

You can turn the front dome light off with its switch, right?

??? A a "hard" ground on the passenger feed should make fuse 12 blow...

Assuming everything is wired correctly-
If the passenger door lights stay on, either the PK (Purple /Pink) wire is shorted to ground (bad switch?) or the diode with PK wires is bad (reversed/shorted internally). IF the latter, you also have a short to ground from the other side of the diode (PW or RU wire).

Disconnect all but the PK wires from the diode. Then see if the passenger side switch turns the passenger door lights on and off. (And what happens with the front interior light.)

Thanks Ron!

I'm referring to the PK, PW, or RU wires as the feed side of the circuits. It looks to me that opening the door "closes the circuit to ground," I have the condition you mention above that I underlined (hard ground/short to ground...tomato/tomahtoe.) I'm reading a ground on the P/K wire, which I believe is closing the circuit and causing the door lights to come on. The front dome is also being affected, but I didn't finish testing yesterday 'cause it started raining.

All my testing at this point is without the switches, domes, or relay in the circuit.

Where is the diode located? Knowing the routing of the wires would really help me find it.

[David T]

Take a look in the Parts Manual at 3-7-0 to 3-7-4 for the wiring harness routing. The diodes are in 3-7-3 #13 & 14.

[Rich_NYS]

Take a look in the Parts Manual at 3-7-0 to 3-7-4 for the wiring harness routing. The diodes are in 3-7-3 #13 & 14.

Thanks, that's what I was looking for....I printed the page for reference.
I'll test at the diodes next to further isolate the issue, as well as try Ron's idea to isolate the passenger side.

[Ron]

Thanks Ron!

I'm referring to the PK, PW, or RU wires as the feed side of the circuits. It looks to me that opening the door "closes the circuit to ground," I have the condition you mention above that I underlined (hard ground/short to ground...tomato/tomahtoe.) I'm reading a ground on the P/K wire, which I believe is closing the circuit and causing the door lights to come on. The front dome is also being affected, but I didn't finish testing yesterday 'cause it started raining.

All my testing at this point is without the switches, domes, or relay in the circuit.

Where is the diode located? Knowing the routing of the wires would really help me find it.
I'm with you on the maders! But the lights on with the feed grounded had me confused -- At the door light, the P wire is the feed (hot at all times). The PW, (PK & RU) provide ground via the switches/relay...
Anyway, if the PK wire is constantly grounded-
There are three diodes near the accelerator pedal, just covered by the console (if you're lucky ;-).
Maybe separate the two PW wires, at the diode, to help narrow it down.

[Rich_NYS]

I'm with you on the maders! But the lights on with the feed grounded had me confused -- At the door light, the P wire is the feed (hot at all times). The PW, (PK & RU) provide ground via the switches/relay...
Anyway, if the PK wire is constantly grounded-
There are three diodes near the accelerator pedal, just covered by the console (if you're lucky ;-).
Maybe separate the two PW wires, at the diode, to help narrow it down.

That's the plan, man....!

Yes, the The PW, (PK & RU) provide ground via the switches.....and with the fuse pulled and the circuit opened at the switches, relay, and domes, I'm reading a ground on the PK wire. So my thought is that part of the circuit is being "closed" and lighting the passenger door.

No rain today....I'm on my way to pick up where I left off yesterday, will report back soon!

[Rich_NYS]

I think there's a ground on the PK wire in the door wiring. I can see it fluctuate when I move the passenger door.

Ron, I see now how I confused the issue: I'm calling PK the "feed" side of the door circuit, and considering P the power feed. I should be calling P the feed, and PK=switching side(?)

.....getting into the door now.

Sent from my LGL164VL using Tapatalk

[Bitsyncmaster]

I think there's a ground on the PK wire in the door wiring. I can see it fluctuate when I move the passenger door.

Ron, I see now how I confused the issue: I'm calling PK the "feed" side of the door circuit, and considering P the power feed. I should be calling P the feed, and PK=switching side(?)

Anyhow...getting into the door now.

Sent from my LGL164VL using Tapatalk

You can pull the door lights easy and get to see most of the wiring without taking the door apart.

[Rich_NYS]

You can pull the door lights easy and get to see most of the wiring without taking the door apart.

Thanks Dave, that's what I did....there was a ground on the wiring in the door, closing the circuit & keeping the door lights on.

Learning about the diodes was super helpful in isolating the issue.

All good now....thanks guys!