So, I'm installing a keyless entry unit into my 240 last night. It's a Pursuit model PRO 9845B. Not a bad little unit. Anyways, I'm just hooking the bare necessities up just to get it to actuate the locks.

Looking at the service manual for the 91-94, there should be an Orange/Black wire coming off the driver side door latch to tell the timer to lock/unlock the door. My car has both an orange/black and an orange/blue. The orange/blue wire was an unlock signal for the 89-90 model.

My unit is supposed to be able to do positive pulse and negative pulse setups. I've hooked the wires up by the book as if I were installing on an 89-90 model. My unlock signal is attached to the orange/blue wire and my lock signal is attached to the orange/black wire. Both are hot all the time with no ground. The latch completes the ground depending if it's going from lock to unlock or vice versa and the completed signal wire tells the timer what to do.

The interesting part is that I have remote unlock capabilities, but not remote locking right now. I'm pretty certain that I've hooked my wires up correctly on the low voltage signal wires, and my remote unit should be acting as a ground complete, not trying to send voltage. I'll be double checking to make sure that the unit is indeed trying to ground the signal out after work.

I'm just after some ideas or maybe even if I just missed something. Broadfield posted this picture in an old thread:



This looks to be for the unlock circuit to me, though. If it turns out my unit is trying to send a positive signal instead of grounding out the signal, I'll just hook up a relay similar to this on the locking circuit.

EDIT: Here's the install manual. I have only hooked up the two constant 12v power supplies, the main ground, and the red and green lock/unlock signal wires. I was going to make sure that the main keyless function was working before I hooked up the lights, door switch, and 12v switched power.

The 89 FSM wiring diagram:

The 89 FSM pinout diagram for the Lock Timer. This page proves that the timer utilizes two ground out switches

The 91 FSM of how my car is supposed to be set up:

Hopefully Broadfield will pop in here and answer you. I'm pretty sure he knows.

Toby and I talked on the phone. It's something he's never seen before, but together, we figured it out.

The system is a single wire system like it should be. I did some tests and the orange/black works like it's supposed to. The only odd part is that when you ground out the orange/blue, it unlocks the doors as well.

My guess is that Nissan tossed old chassis harnesses from the 89-90 model in the early model verts. My car was produced in '91, so I could see them using leftovers in a low production run. Because of that, I get the extra wire on the chassis harness, but it doesn't do anything.

Anyways, I wired in the relay like I'm supposed to, but I think I have a bad remote unit. When I lock it, the remote's lock circuit is only drawing ~4v, which isn't enough to trip the relay and cut the orange/black circuit. I ruled out poor grounding of the unit, so I'm stuck with a possible defect. I'll go back to my vendor tomorrow and see what we can do.