M52 86' E30 Swap - How do I wire a check engine light

[me30wW]

Have an m52 motor swapped 86 e30, its an early model which did not come w/ a check engine light. How would I wire in a check engine light? Its OBDI swapped. Thanks in advance!

[DesertBMW]

In Europe there was no "check engine" light on any of the BMW all the way until year 1999. You could wire in 12v LED, provide 12+ to it then negative trigger will come from the DME, that is your check engine.

[me30wW]

You could wire in 12v LED, provide 12+ to it then negative trigger will come from the DME, that is your check engine.

One last question, which wire is the negative trigger?

I thank you kindly friend!

[2mAn]

I think its pin8 on the X20. Gray wire IIRC