e38 bench harness question
09-25-2020, 09:13 AM
#1
On The Tree
Thread Starter
e38 bench harness question I'm assembling a bench harness for my e38 ECM. I'd like to incorporate a LED to indicate when the ECM is powered on. It would be simple to just wire the LED into the power switch, but I'd rather if the LED actually indicated the power status of the ECM. This way, the LED would go out if the ECM got bricked or unplugged.
What could I pin the LED to in the e38 ECM, that would hold continuous power for as long as the ECM is powered up? The powertrain relay wire is tempting, but I suspect that might go off after a few minutes of inactivity. I could also potentially use one of the 5v reference wires, but I'm afraid those might also cut off after a short period of no crank signal.
Any suggestions?
What could I pin the LED to in the e38 ECM, that would hold continuous power for as long as the ECM is powered up? The powertrain relay wire is tempting, but I suspect that might go off after a few minutes of inactivity. I could also potentially use one of the 5v reference wires, but I'm afraid those might also cut off after a short period of no crank signal.
Any suggestions?
09-25-2020, 12:47 PM
#2
On The Tree
Thread Starter
Looking over the e38 pinouts, the "check engine" lamp caught my eye. Will this lamp stay illuminated the whole time the ignition is on but the engine is not running?