I've been inspired by Chris' videos (Phoenix Engine Management on YouTube), and I have decided to include an extra LED in my 3UZ fuse box for the CEL. As I understand it the CEL (or MIL) is triggered by a switched GND provided by the ECM, so duplicating this indicator in the fuse box or engine compartment is simply a matter of running a wire to it in parallel with the dashboard CEL and supplying the other side of the LED with 12v from an IGN source.
Can something similar be done for the other "important" warning lights, e.g., the Oil Pressure Light and the Alternator Light? From the wiring diagrams it looks like MOPS on the ECM receives a switched GND from the oil pressure switch, and RL on the ECM illuminates the Alternator Light when it receives GND from the alternator "L" wire. I don't actually need to do this, because my fuse box is inside the vehicle, but it might be useful for someone whose fuse box is located under the hood/bonnet (where the dashboard would not be visible during testing and maintenance). Thoughts?
Can something similar be done for the other "important" warning lights, e.g., the Oil Pressure Light and the Alternator Light? From the wiring diagrams it looks like MOPS on the ECM receives a switched GND from the oil pressure switch, and RL on the ECM illuminates the Alternator Light when it receives GND from the alternator "L" wire. I don't actually need to do this, because my fuse box is inside the vehicle, but it might be useful for someone whose fuse box is located under the hood/bonnet (where the dashboard would not be visible during testing and maintenance). Thoughts?
