I went to the junkyard and got what I thought were all the components of the trunk light I needed. I have a base model, no light and no wires for the light.

I got the actual trunk latch and wire on the latch. I got the wire all the way back to the harness it was plugged into on the side of the trunk.

I got the light bulb and holder and wire harness for it. That harness had two pink wires (combined together at the bulb connector, and one brown wire that connects to the wire going to the latch.

Got it all wired up. Put the fuse back in the circuit with the trunk open, viola - trunk light worked! Yea! So far so good.

Closed the trunk - light stayed on. Booo! Bad news!

After re-examining the wire diagram that came with my Haynes manual, I have the pink wires from the trunk bulb socket/harness connected to the same pink wire the dome light is on. It has power all the time.

I have the brown wire coming from the light bulb socket and harness connected to the trunk latch connector wire. The latch itself also has a black ground wire to the trunk lid - separate and connected.

Now because the wiring circuit appears to be so simple, my best guess as to why the light goes not go out when I close the trunk lid is that the trunk latch I got from the junkyard is damaged, and the contact switch inside the latch mechanism is not properly opening the circuit when I close the lid.

The only other thing I can think of is that there is some kind of resistor pack/diode spliced into the wiring harness for that light circuit that I just did not see when I got the parts. I don't think so, but I thought I would ask.

Does anyone have a clue what I need to check? I have a multi-meter, so should there be continuity between the latch and the connector wire when the trunk is open and no-continuity when the lid is open? If someone has a working trunk light, maybe you can tell me what I need to see in order to know if the latch (and the contact switch inside it) is good or bad.

Right now, I have the whole thing disconnected as I do not want my battery to drain to nothing because of this.

 

Trunk switch completes the ground when open. Which is in the latch I think?

 

The switch is built into the trunk latch, so yes.

I assume that the switch closes when the trunk opens thereby completing (closing) the circuit.

When you close the trunk, I assume that the switch opens, breaking (opening) the circuit.

However, when it does not matter if my trunk is open or closed, the light shines. That is why I think my trunk latch is busted.

Can you put a meter on it when open to see if there is continuity or not?

 

I would manually close the latch so you can see if its shorting off the latch rod or something. Otherwise grab a new latch. Yea the switch just completes the ground when opened for the light to come on.

 

It was a bad latch. When I got another one, the whole thing worked perfectly. The latch had bad contacts on the switch inside and did not properly close when the lid opened.

 

Some trucks like the 1993 Dodge Dakota have a hood light. The switch is built into the light. When you open the hood the light comes on because it's not level... mercury switch or something. Go to the salvage yard and yank one out of a truck like that. Then all you need to wire is a 12v wire from the battery. The trunk is the ground. KISS