Worked on the door ajar wiring, found out that the BCM will cross feed through the older message center. As soon as I connected the message center the courtesy lights would come on and the chime in the BCM would start going ding, ding, ding. The 1995 LeBaron only has a single door ajar light and uses two diodes in the relay center to allow either door to illuminate the light. I took a couple of diodes I had around and put them into the circuit from the message center into the harness. Now either door will turn on the courtesy lights, but only the driver's door will turn on the ignition cylinder light.
Next issue was the headlight switch, the 1990 up LeBaron and Daytona do not use a pull knob style light switch, they use pod or later a combination switch. I had already added the relays for running and headlights, but, any time I connected the switch using the B1 (headlight) and B2 (running lights) as a ground and then plugged in the panel lamp dimmer circuit or electronic dimming, the BCM would start alarming. I finally, after a look at the later light switch functions, reversed the B2 and K connections. This puts the panel rheostat and electronic resistor always to ground. Adding a 980 ohm resistor in the panel light dimming circuit made it at least functional, backwards, but functional.
Then it was test other warnings, like low fuel, low washer fluid, trunk ajar. Low washer fluid worked right away, no issues, low fuel, another change in function, on the older system, either a thermal switch powers the low fuel light or an electronic module. Both are there to delay the light until the low fuel contact stays on for a bit. Now it is part of the BCM and it grounds the light after the same delay. The older message center has a ground trace that runs through the 3 panel lights and the low fuel light. In order for the BCM to control it, the light had to be powered, there was already a pin to the hot side, just no connection to it. I added the wire from the BCM and then cut the ground trace and soldered a jumper across from the 12V ignition power to the light on pin from the extra circuit. Worked perfectly, fuel below 1/8 tank, after a short delay Ding, Ding and low fuel light came on. Trunk ajar was interesting, switch was there, all connected, light would not work, even grounding the lead to the latch screws. No ground from the trunk lid to the body. 3rd brake light and license light worked fine, they have a gray ground wire into the rear harness. I tapped into that and grounded the trunk lid.
