Door pin switch wiring

[4BY4ADV]

A few months back I replaced the aftermarket alarm the PO had installed with a model that had a two-way remote and a mile + range. I re-used the door trigger wire that the PO had used, located under the dash to the left of the steering column.

Last week I started getting alerts that a door was open every time I set the alarm. Yesterday I had some time to kill and decided to figure out what's going on. I pulled both door switches and both operate properly. I snipped the trigger wire and hooked up my multimeter, no change whether the doors are open or closed.

For the hell of it, I thought, let's turn on the headlights and then open the door. I get the audible warning that I left my lights on, close the door and the warning goes away.

Before I go through the hassle of running new wires just for the alarm, is there simple explanation/fix that I should be looking at?

Thanks!

 

[4BY4ADV]

Alright... so I decided it wouldn't take long to determine which wire coming from the switch was ground/door open, open/door closed. Driver side checked out, two yellow wires and one black wire. Black was open until the door opens, then it's ground.

Switched to the passenger side and I find that there's only two wires, both yellow. There was a third wire, black/purple that was grounded to the body and appears to go into that loom where the two yellow wires are. When I pulled the switch, I found that there are only two contacts on the body side of the loom, though three contacts on the switch side like the driver side. Multimeter shows continuity between the two yellow wires, so I'm assuming someone bypassed the passenger side door switch? (also, the audible alert when a door is open and the headlights are on is not triggered by the passenger door)

Can someone confirm that their passenger door switch has three wires?

If that's the case, can someone point me to the P/N of the body side of the harness so I can correct the PO's stunt?


Okay, so found the interior wiring in the FSM. I thought the switch was just creating a ground when open, but the wiring appears to show it's connected to a fuse, which leads me to believe it's got power on one end. Either way, I see now that only the drivers door triggers the audible alert for the headlights on/door open/ignition off. So no need to diagnose the passenger door switch, that's truly a 2-wire while the driver is a 3-wire.

So now I'm even more confused why the system isn't working. Also I'm wondering how the signal wire would work if there is no dome light... which I don't have. I feel like it would be an open circuit.


I don't get what changed and how it worked.... and now it doesn't.


**update**

Gave up. I was spending too much time tracing wires to find a shorted ground. Everything "appears" to work fine other than the signal going to the alarm. Rather than continue going without having a working alarm, I bought two aftermarket single wire push sensors like what you would use for a hood, drilled new holes next to the factory door switches and ran additional wires just for the alarm. Not the most elegant solution, but 100X easier than continuing to diagnose an odd electrical gremlin.