Electrical Diagram Help?

Optikal · 12-10-2004, 09:41 AM

I'm using the shutdown controller sold on mp3car.com. It has an input for the ignition signal which it uses to turn the computer on/off. I want to get a bit more fancy and have the computer turn on whenever the ignition is on OR the dome light is on. I figured I could just splice the IGN wire and dome light power wire together with a couple diodes to prevent reverse current, then run that to the IGN input on the shutdown controller. However, looking at the wiring diagram for my dome light, it appears that its power wire is always "hot" and the lights operation is controlled by applying and removing the ground. So if I were to splice the power wire and send that to the shutdown controller, the shutdown controller would think the dome light was always on. Any idea how to solve this? I'm thinking something with a relay may be the solution, but my electrical skills are a bit rusty... Attached is the wiring diagram for the dome light.

MatrixPC · 12-10-2004, 10:16 AM

Just wire it with a relay to the door lock pulse.
- From power source/always hot (battery) to terminal 85 and 30
- From door switch (- pulse) to terminal 86
- Terminal 87 connect to SDC ignition signal and the real ignition signal. Isolate the 2 sources with diodes like this
---- Relay 87 --- DIODE ---| SDC IGN
---- Car ING ---- DIODE ---| SDC IGN.

[edit] Of course, you must fuse all power sources [/edit]

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